The Paxman Machine Shops
1982 to 2003

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Introduction

The importance of the machine shops in the life of Paxman would be hard to overstate. They undertook the manufacture of an extensive range of parts, both for the new engine build programme and the Company's Spares and Overhauls businesses. Apart from some specialist items such as pistons, valves, and fuel injection equipment, virtually all key engine components were machined in-house. These included crankcases, cam troughs, free end covers, sumps, connecting rods, bearing blocks, cylinder heads, cylinder liners, injector housings, and rocker levers.

The machine shops and their work were largely hidden from the public's view and consciousness. However, until the transfer of manufacture to the Mirrlees factory at Stockport in 2003, they constituted the largest part of Paxman's manufacturing activities. They employed more people than any other single function in the business. Furthermore, up to the late 1990s Paxman had probably one of the largest and most advanced machining facilities on a single site anywhere in East Anglia.

During November 2003 manufacturing at Paxman's Standard Works finally came to an end. By this date much of the newer equipment in the machine shops had been transferred to Stockport. A small number of other machine tools were kept for the Repair & Overhaul facility which was retained at Colchester. The remaining machine tools were offered for sale at an auction held in Paxman's main machine shop on December 2nd, 2003. By the summer of 2006 virtually all the machine shops had been demolished during clearance of the north side of the Hythe Hill site for housing development.

Many years of hard work and professional commitment went into developing Paxman's considerable machining capabilities. The facilities and expertise which were created have now been irrevocably dispersed. It is sad to reflect on the fact that the wealth of manufacturing knowledge, skill and experience built up in the Company over 138 years is no longer available to pass on to future generations.

Exacting Standards of Technology and Skill

To fully appreciate the technology and skills which were employed in Paxman's machine shops requires an understanding of some key features of the Company's engines. They are large high speed diesels, expected to operate reliably for many years, often under arduous conditions. The high internal working pressures and temperatures associated with compression-ignition engines call for robust construction and manufacturing within fine tolerances. High speed versions of such engines make yet more exacting demands. Higher reciprocating speeds impose much greater forces on the bearing surfaces of connecting rods and bearing blocks so tolerances and surface finish are more critical. Higher piston speeds make it essential for cylinder liners to be machined within tighter limits, again with an exceptionally high quality surface finish. The large dimensions of some components posed additional challenges. Items like crankcases needed attaching to jigs with great care and accuracy to maintain fine machining tolerances over distances of several feet. A further factor to be taken into consideration was the variety of materials with which the machine shops worked. These included iron castings, SG (spheroidal graphite) iron castings, steel forgings, aluminium alloy castings, mild and stainless steel.

Small Batch Production

Paxman was never a volume manufacturer of diesel engines like Perkins of Peterborough (now Caterpillar), Caterpillar, or Cummins. During the final decade of manufacturing at Colchester an output of forty or fifty new engines a year would have been considered good. In addition to the limited number of new engines produced annually, there were other factors which dictated a small batch approach to production. The high stock value of finished components, and regular design improvements, made it uneconomic to machine larger batches of individual components than would satisfy anticipated requirements for the next few weeks or months. Similar considerations applied to the manufacture of spare parts. Paxman stocked a wide range of spares for many older engine types no longer in production. The need to limit the amount of capital tied up in such stock, and the fact that many line items sold only in small quantities, again called for small batch production. Unlike volume manufacturers, it was not an option for Paxman to set up machines for long production runs employing mainly semi-skilled machine minders.

The small batch approach had implications for Production Engineering staff, for shop managers and supervisors, and not least for machine operators. Short runs necessitated the frequent setting up and taking down of jobs, often involving considerable non-productive machine time unless the machine was capable of using palletised jigs. Because of the practicalities of frequent setting up, and a need to maintain high quality standards, Paxman's practice was to employ a high proportion of skilled machinists in its machine shops; apprentice-trained craftsmen capable of working independently from engineering drawings, of setting up machines accurately for a range of different jobs, and of closely monitoring the quality of their own work during production runs.

Machine Shop Management and Supervision

Board level responsibility for management of the machine shops lay with the Works (later Manufacturing or Production) Director. From 1979 this was K A (Ken) Ward who joined the Company from CAV (1). He was succeeded in June 1983 by C H M McAusland, a fiery Scotsman memorable for his ferocious bark, who was recruited from the motor industry. (The then Managing Director, Jeff Herbert, had come from the motor industry.) Colin McAusland left in November 1985 to advance his career with a company in North East England. By this time the Managing Director was Jack Fryer who brought in a former Lincoln colleague to fill the post. K G (Ken) Wills was previously Production Director with Ruston Gas Turbines at Lincoln and remained with Paxman until his retirement in 1991. In August 1991, at the age of 30, M E Congdon was appointed General Works Manager, responsible for the total manufacturing function on the Colchester site. As a student Mike Congdon had been sponsored by Paxman on the BSc Industrial Engineering course at Hatfield. He subsequently worked in Production Control and a number of other positions in manufacturing at Paxman (apart from a 10 month stint at Betts) before assuming overall responsibility for the function (2). He was later made Manufacturing Director and held that post until leaving in June 1997. Responsibility for the manufacturing function was then given to B D (Brian) Pash, at that time the Company's Personnel Manager, until the appointment of Steve Dearing as Production Director in July 1999.

Reporting to the Works Director was a position sometimes described as Machine Shop Manager: this title changed from time to time. In the mid-1980s the post was held by Peter Tidy who had the title Assistant Factory Manager. After Peter Tidy left in March 1986 there followed a succession of people in the post. The relatively short periods for which each remained in post is indicative of the difficulty of the job and the heavy pressures imposed on those doing it. Among those who succeeded to the position were A R (Alan) Creasey, David Gulliford (July 1988 to June 1989), I D (Ian) Raymant, M T (Martin) Pryke and M J (Mark) Burrows.

During the early to mid-1980s, at the next level down in the management structure were Superintendents. By 1985 there were only two: Peter Wilson in No 1 Machine Shop and Norman Williamson in the Fabrication Shop. About five years earlier, as far as can be recalled, Martin Pryke was Superintendent of Nos 1 and 2 Shops and crankcase machining, with about 250 operators under him, while Peter Wilson was Superintendent of Nos 3 and 4 Shops. By the mid-1980s the Superintendent concept was becoming an anachronism and no more were appointed after Norman Williamson and Peter Wilson left the Company in the late 1980s.

Reporting to Superintendents, and later direct to the Machine Shop Manager or equivalent, were Foremen or Supervisors. These were recognisable on the shop floor by the red lapels on their dark grey warehouse coats. Among the long-service machine shop foremen in the mid-1980s were Bob Bush, Ernie Taylor and Peter Downing. During the early 1990s the job title of Foreman or Supervisor was replaced by that of Section Leader and the nature of the job changed. In addition to general supervision of staff on their sections, Section Leaders were responsible for juggling work priorities. They had to reconcile the conflicting demands of new engine build, the Development Department and Spares and Service, each pushing for their own urgent requirements to be met first. On top of this was the task of constantly reviewing what raw materials, machines and men were available to maximise production on their respective sections. Section Leaders in the machine shops during the late 1990s were David Brine, Mick Read and Graham Stocks.

Skilled Machinists

One of the striking features of the Paxman workforce in the machine shops (and indeed in Engine Assembly) was the very high proportion who had served formal craft apprenticeships, often with the Company, or had equivalent training and experience. Trying to recruit good machinists, especially experienced CNC operators, in the late 1980s and during the 1990s became increasingly difficult as the engineering industry declined in the Colchester area. Many skilled men, having experienced the pain of redundancy or a succession of redundancies, left the engineering industry for more financially rewarding work and greater job security elsewhere.

Although a machinist's apprenticeship covered most aspects of machining, it was common in the industry for people to develop a career in one particular form of machining depending on their interests, abilities and opportunities. They would generally become, for example, one of the following - a turner, miller, borer, grinder, driller, marker out, CNC operator, or inspector. All these crafts were practised in the Paxman machine shops.

At Paxman the skilled machinist was responsible for setting up his (I can't recall any female machinists being employed by the Company during the 1980s or after, although many were during WW2 and the years which followed) own machine for each job, working from engineering drawings and planning sheets. The latter, prepared by Planning Engineers, specified the sequence of operations to be carried out on a component and gave detailed instructions for each operation. They also listed any special tools, jigs or fixtures required and the time allowed for the job. The manufacture of a component such as a bearing block might involve as many as 55 or more separate operations, not all carried out on the same machine or by the same operator. Whilst machining a batch the operator was responsible for continuously checking his work to ensure dimensions remained within the specified limits. Although there were several inspectors in the machine shops, after the mid-1980s operators were given increasing responsibility for inspecting their own work under a system called Operator Control. A man had to stamp his clock number on the paperwork accompanying each batch after completion; a procedure which allowed for full traceability - even years later. Given our human nature mistakes will happen but the high value of many components meant that errors could be very expensive. It was often suggested that many 'mistakes' were quietly laid to rest by the night shift in the murky depths of 'The Pond' on the north side of the site. It is a sobering thought that some individual operators were responsible for looking after machine tools which cost literally hundreds of thousands of pounds.

Production Engineering

Any account of the Paxman machine shops would be incomplete without reference to other departments which supported them. Perhaps most important was the Production Engineering Department (PED). Paxman was fortunate in being able to attract some highly able and well motivated engineers to work in PED. That is not altogether surprising because of the variety of interesting work and challenges it offered. This included investigating new production methods, planning new factory layouts, and preparing proposals for major capital investment in new plant. The Department played an absolutely central role in the rationalisation and re-organisation of the machine shops which took place between 1990 and 1993. Its staff were responsible for the selection of new machine tools and their subsequent commissioning, as well as planning the extensive relocation of existing machines. Other important aspects of their work were the development of programs for CNC machines and resolving problems which arose on the shop floor in the course of production.

The Department worked very closely with the shop floor. Production Engineers spent a substantial amount of their time with operators which gave them a good understanding of the production environment and practical problems faced by the shop floor. The good working relationships were aided by the fact that some machinists, on completion of their apprenticeship, continued their training to achieve National and Higher National Certificate qualifications and then progressed from the shop floor into PED. In that Department their knowledge of the shop floor, the people who worked on it, and their practical experience were invaluable. One wonders how many other factories managed to achieve such a close working relationship between their production engineers and machinists.

From 1985 to May 1998 PED was led by John Pyle who had previously worked at the Royal Ordnance tank factory in Leeds. He was succeeded by Brian Miller, a much respected and long-serving Paxman man, who was responsible for this function until the machine shops closed in 2003. He subsequently advised the Stockport factory on machining issues after manufacturing was transferred there from Colchester.

Works & Plant Department

Another department closely supporting the machine shops was Works & Plant. One of its main responsibilities was the maintenance of all buildings and plant on site and the provision of services such as electricity, water, steam, and compressed air. A vitally important aspect of plant maintenance, requiring a high level of knowledge and expertise, was that relating to machine tools. The task became increasingly demanding during the 1980s and 1990s with the introduction of ever more complex electronic control systems on machine tools. The problem was compounded because the more sophisticated machines were precisely those on which Paxman relied most heavily to meet its production commitments. They were also the most expensive machines to have lying idle. Breakdowns are a fact of life with any machinery but members of the Works & Plant Department were put under considerable pressure to resolve problems as quickly as possible so that production could be resumed.

For many years the Department was managed by A H Barnes. After Alan Barnes left in 1992 overall responsibility passed to John Pyle who took it on in addition to his existing work as Production Engineering Manager. Day to day management of Works & Plant increasingly devolved on David Baxter, whose quiet manner belied his considerable knowledge and ability.

Introduction of NC (Numerical Control) Machine Tool Technologies

A number of conventional machine tools, including one or two probably acquired during World War 2, were to be found in Paxman's machine shops right up to 2003 when they closed.

NC machines were first installed at Colchester in the late 1960s. Their operations were controlled by a punched paper tape fed through a tape reader on the machine. Tapes were produced remotely by the Company's Production Engineers who were responsible for developing the programs of machining operations to be carried out on components. The actual operators of NC machines were unable to make any changes to the programs stored on tape. Alterations had to be made by the Production Engineering Department and a new tape produced. Paper tape continued to be used as the medium to store and input programs into the memory of later CNC machines until the development of DNC systems.

The next stage in the development of NC technology was the CNC (Computer Numerical Control) machine. The first of this type at Paxman was a Kearney & Trecker HMC1500, installed in the mid- to late-1970s. In CNC machines programs are run from the memory of the computer within the Numerical Control. The practical implications are that programs can be edited at the machine, which is quick and convenient. In time the controls were developed to provide menu driven "conversational" programming which allows programs to be written at the machine. Some of the programming on Mazak machines at Colchester was carried out in this way.

The third step in the use of NC technology at Paxman was the introduction of DNC (Distributed Numerical Control). With this all programs were stored on a remote Personal Computer and distributed to the various machine controls via a network. Programming was carried out within the Production Engineering Department and the programs then downloaded to machine tools on the shop floor. Paxman used a DNC system from D-Log very effectively until the machine shop closure.

Hardening Processes

Diesel engines impose heavy loads on the surfaces of many of their components. To reduce wear and achieve a satisfactory service life it is essential to harden various components after they have been machined. In addition to some conventional heat treatments, Paxman employed the following hardening processes:

Gas Nitriding, which became an important process for Paxman components as engines were uprated and imposed greater stresses on their components. A large Birlec "Top Hat" furnace was introduced in the 1960s to Nitride harden the Ventura and Valenta crankshafts manufactured in the Colchester machine shops. This was supplemented in the 1970s by a shuttle furnace to nitride Valenta connecting rods and bearing blocks and Ventura and RPH bearing blocks.

Rik Alewijnse, who worked for Paxman for nine years, relates the tale of the 'big bang' in the Birlec furnace. This was sited in the old riveting tower at the western end of No 3 machine shop. Some time around 1979 - Rik remembers he was then an apprentice - there was a huge bang. He was in the Jig & Tool Drawing Office at the time and everyone felt the building shake. The top hat of the furnace was blown into the air. Fortunately, no one was hurt, but Rik did hear tell of a machinist in No 3 shop who lost his contact lenses.

The Birlec comprised electric heating elements in a refractory brick base. Crankshafts to be nitrided were stacked up on special stands and the steel "top hat" was lowered down over them by crane and bolted down. Nitriding uses ammonia gas (NH₃) fed into the furnace when it and the steel parts in it are hot. The ammonia breaks down: the nitrogen combining with the components' surface metal to form iron nitride (FeN) and the hydrogen gas (H₂) being released as waste. The process takes a couple of days after which time the atmosphere in the furnace is purged to eliminate any remaining ammonia and hydrogen before it is opened. At the time, air was used for this purge operation. On the fateful day there must have been a hot spot somewhere inside and the remaining hydrogen reacted with the oxygen in the air to produce a highly exothermic reaction, a sort of contained Hindenburg disaster. Afterwards, Paxman bought in pure nitrogen for the purge and the nitrogen "pallet" of, we think, 12 cylinders, stood outside No 3 shop.

Sulfinuzing (a proprietory name) was used until the mid-1990s. It is a salt bath process in which nitrides are diffused into component surfaces to enhance fatigue strength and impart improved anti-scuff properties. This method increases surface hardness to only to a very limited depth (.0012"). When Sulfinuzing became environmentally unacceptable because of its use of cyanide salts, a fluidised bed furnace (pictured right) was introduced to undertake ferritic nitrocarburising as a direct replacement process. In this process, the retort into which the components are placed is filled with aluminium oxide 'sand' which is fluidised with air and heated. Hardening is carried out by passing the processing gases through the charge.

Induction Hardening. Facilities at Paxman included scanning shaft hardening and single shot hardening machines and one of the few Delapena "tooth by tooth" gear hardeners to be installed.

Washing, Cleaning and Surface Finish Processes

In addition to hardening, a number of other processes were used within the Company to support component manufacture. During the 1980s washing and cleaning processes were grouped together in a workshop attached to the old No 2 Engine Erecting shop. These included a tunnel spraywash machine, acid pickling tanks for de-rusting, phosphating tanks, a blackodising plant for surface treatment and enhancement, and painting facilities. Also in this area were the pressure test facilities for checking the integrity of cast components and joined sub-assemblies. This was done by blanking off openings in the casting or assembly and injecting water under pressure into the internal spaces. Any subsequent drop in pressure or water leak indicated a flaw or defect. In the 1990s all these facilities were integrated into the main machine shop when No 2 Erecting Shop was closed as a workshop.

Chrome plating was carried out, mainly on bearing blocks until gas nitriding of these components was introduced in the late 1960s. Paxman continued to do its own chrome plating of components for spares, into the late 1970s. Other plating processes, including zinc and tin, were carried out mainly in support of the Deltic engine. These operations ceased in the 1980s.

Virtually all these processes involved the use of hazardous chemicals and were therefore closely monitored by the Metallurgical Laboratory staff. Also, those who worked on the more hazardous processes were kept under regular health surveillance by the Medical Centre.

The Six Dedicated Machine Shops - c.1982 to 1990

Background

Martin Pryke joined Paxman in 1959 and spent over forty years in its machine shops. He recalls that when he joined the Company most of the machining facilities at Standard Works were housed in No 1 machine shop, adjacent to St Leonard's Road. In No 1 bay, nearest St Leonard's Road, were turret and capstan lathes and some drills. Next, in No 2 bay, at the top end nearest Standard Road, the profile machining of camshafts was undertaken. Also in this bay were the milling section, centre lathes, and more drills. In the large No 3 bay were crankshaft machining and, at the top end, the vertical borer and some large drills. The whole of bay 4 was taken up with crankcase machining. In the shop were four foremen, one in charge of each bay. In 1971 Martin was made up to foreman of the crankcase bay, the youngest ever foreman at Paxman. He was then only 27 and Company policy stipulated that applicants for such positions should be aged at least 30. As an indication of how busy the shop was at this time, Martin says that one day he counted a hundred crankcases on his section, some of the smaller RPH ones being stacked three high. It made a lot of work for the crane driver and his slinger if one of the bottom crankcases was required!

In addition to the machine shops at Standard Works supporting diesel engine manufacture, the Fabrication Department had its own machining facilities. These are believed to have continued as separate dedicated shops up to the 1980s. They included large vertical borers and planers to support the manufacture of filters and boilers.

For many years Paxman also had machine shops at Britannia Works ('the Brit'). As at 1965, the Company's centenary year, all cylinder heads and blocks were produced at the Brit together with vast quantities of smaller components machined from bar material. Also manufactured here were the majority of spares for engines no longer in production (3). Sometime after the manufacture of large shell boilers was transferred from Standard Works to Lincoln in 1967 a site reorganisation took place (1969/70?). The cylinder head gang at the Brit moved up to Standard Works, into No 1 bay of No 1 machine shop. Not long afterwards that decision was reversed and cylinder head machining went back to the Brit. From that time cylinder heads were also assembled there. When the Brit closed in 1982 all this work came back to Standard Works and was located in No 6 machine shop.

From 1982 until the end of the 1980s, machining activities on the Hythe Hill site were concentrated in six dedicated machine shops, each responsible for producing different types component. The Annual Report to Employees for the financial year 1985/6 stated "The concept of dedicated autonomous workshops for each of the major components e.g. crankcases, cylinder heads, connecting rods/bearing blocks, cylinder liners, continues to be developed, . . ." The work done by each of these shops and some of the machine tools employed in them during the mid-1980s are described below.

Plan of Standard Works before the rationalisation of 1990-93.

No 1 Machine Shop

No 1 was located in one of the oldest buildings at Standard Works, on the northern edge of the site adjacent to St Leonard's Road. In the mid- to late-1980s Peter Wilson was the Superintendent responsible for running it. The main work undertaken in No 1 at that time was the machining of cylinder liners, including those for Deltic engines. The latter were of complex design, made in steel and, for minesweepers, in stainless steel.

Up to the mid-1970s crankshafts for the RPH, YH, YJ and Y3J engine ranges were bought in as forgings and machined in No 1 before being heat treated in-house. After this time YJ and Y3J crankshafts were bought in already machined as the supplier argued the contract was not economically worthwhile without the additional work. Paxman continued to buy in crankshaft forgings for RPH and YH engines until about 1982. These were first turned and then put on a 'pinner' to turn the crank pins. A further operation was drilling the oilways with a gun drill. The final operations were grinding and polishing. After 1982 all crankshafts were bought in already machined but grinding and polishing of crankshafts for the Repair & Overhaul and Development Departments continued until about 1988. Three people heavily involved in this specialised work were Terry and John Blanc (brothers) and Doug Rudkin.

Another specialised operation undertaken in No 1 up to the early 1960s, in a dedicated camshaft cell, was the machining of camshafts for 4, 6 and 8 cylinder RPH engines.

It is appropriate to mention here that between the production area in No 1 and the wall along St Leonard's Road, was the Apprentice Training School. This had been set up by Malcolm Frost during his time as Training Manager. In the mid-1980s the Training School had two full time instructors, Sam Johns and Peter Smith. Craft apprentices would spend their first year in the school learning basic practical skills in disciplines such as fitting, machining, fabrication, welding and electrical work, except for the one day a week they studied at Colchester Institute on day release.

No 2 Machine Shop

No 2 adjoined the south side of the Old Office Block and was behind an office (occupied by Brian Basting, Production Controller) which faced west out onto the yard. It was responsible for machining connecting rods and bearing blocks. Until late 1982 the supervisor was Roly Bond, a well known personality in Paxman who also represented supervisory staff in negotiations with management. He was succeeded as No 2's supervisor by Tom Claydon, then Dave King up to late 1988 and subsequently Steve Clubb.

Among key items of plant in the shop were two Bohle W2 horizontal spindle CNC machining centres. These used a twin pallet shuttle system - one being available for loading/setting up a job while a component attached to the other was being machined. Also in this shop were a Takasawi CNC lathe, internal, external and surface grinding machines, radial drills, milling machines and a vibratory finishing machine - "the Vibro" - used for surface finishing of some small components by tumbling them with wetted stones.

No 4 Machine Shop

No 4 was a long narrow shop situated between No 2 and No 3. The main output was small components turned from both bar length material with automatic bar feed and bar billets manually loaded to the chuck. Among items made in this shop were studs and bolts and injector housings. A number of Warner & Swasey CNC machines were installed (around 1978?). Also in the shop were centreless grinders, external grinders, a Citizen sliding head lathe and a thread roller. At the far end of the shop was the Tool Room under the supervision of Dave Stollery who had been with the Company for very many years.

No 3 Machine Shop

Until 1967, when the building of large shell boilers was transferred from Colchester to Ruston at Lincoln, this area housed the Boiler Shop. By the mid-1980s it was a large general machine shop, mainly machining small castings but also handling larger items such as flywheel covers. The shop housed a wide variety of machine tools, mainly conventional, both large and small. These included mills, lathes, grinders, drills, and borers. During the mid-1980s and up to September 1988, Dave Burmby was shop manager, assisted by Percy Hale. Long serving supervisors in No 3 included Bob Bush and Ernie Taylor.

In the middle of No 3 was a two storey glazed, wood-framed structure known to all as 'The Crystal Palace'. On the ground floor were the shop supervisors' offices. Up some stairs, on the first floor, was the Production Control office. The Crystal Palace was demolished during the Christmas shutdown in 1989, in preparation for the major machine shop rationalisation and re-organisation which took place between 1990 and 1993.

No 5 Machine Shop

No 5 was located in the south east corner of the large machine shop, next to what had been the Deltic Overhaul shop before it became the Fabrication Shop. It handled all crankcase machining, one of the most complex and demanding tasks undertaken by the machine shops. Any mistakes could be exceptionally expensive.

The crankcase machining cell was set up in 1980/81 when new machines and methods were introduced during Les Fisher's time as Production Engineering Manager. The changes reduced the lead time for machining crankcases from 32 to 13 weeks. Two key machines in the shop were the large Bohle V/H CNC portal milling machine and the Kearney & Trecker Moduline CNC machining centre. The Bohle, which could take up to 40 hours or more to complete its program on a crankcase, was capable of automatically selecting and coupling right angle heads and was thus capable of machining five sides of a component at a single clamping. The Kearney & Trecker Moduline was used for lighter milling, drilling, and tapping operations on crankcases.

New working methods introduced in 1980/81 used palletised jigs made by Rohmeld. These were compatible with both the Bohle and the Kearney & Trecker. The palletised jig system allowed a crankcase to be set up on a spare jig while one on another jig was being machined. This allowed greatly improved machine utilisation as previously machines lay idle while a job was being set up and while it was being taken down.

Also located in this cell were the Giddings and Lewis horizontal borer and a line borer for remedial work and repairs on spares crankcases, etc. Then there was the LK CNC co-ordinate measuring machine. With its large granite table and measuring capacity of 4000 x 1700 x 1500 mm this machine was used to measure all the dimensions of a crankcase after machining. The LK's computer subsequently printed out a record of all the dimensions, which were retained for future reference. An expensive machine which did no actual work on a crankcase but told you whether or not you had made a mistake and, if so, how big a mistake!

In 1990 twenty two people worked in the shop on a double day shift arrangement. Martin Pryke was responsible for running it, with two supervisors, Peter Downing and Mick Read (4).

No 6 Machine Shop

No 6 was situated across the yard, to the west of No 1 and No 2, on part of the site of the foundry which had closed in 1979. Steve Clubb was Supervisor in No 6 which was dedicated to the manufacture of cylinder heads. Cylinder head machining was moved into this shop from Britannia Works during the summer factory shutdown in 1982 (5). Among the machines installed in it were Kearney & Trecker CNC machining centres, the CimX NC Machining Centre and the Fritz Werner Duplex Mill.

Parts Manufacturing Rationalisation 1990-93

Although Paxman's strategy of dedicated autonomous workshops for each of the major components was still being developed in 1986, within three years it was displaced by a quite different one.

Will Pavry returned to Paxman in October 1987 as its Managing Director. Under his leadership plans were laid and executed for what was possibly the greatest ever re-organisation of the Hythe Hill site. He was successful in winning GEC ALSTHOM's support and approval for major investment in new state-of-the-art machine tools and site refurbishment. No doubt his case was strengthened by the facts that Paxman was developing its completely new VP185 engine and that its success would depend on having the right manufacturing strategy in place. Nevertheless it was a great achievement for Will Pavry to push through the investment and rationalisation at what was not an easy time for the Company. Externally Paxman faced increasingly stiff overseas competition in its sector of the diesel market and was handicapped by adverse sterling currency fluctuations. On the Colchester site itself no less than eleven redundancy programmes were announced between September 1988 and November 1994, a stark indicator of the pressures on the business. It is a tribute to the vision and commitment of senior management and the Production Engineering staff that such an extensive project was fully implemented, very successfully, in less than favourable circumstances.

In addition to the need for better manufacturing facilities for the VP185 when it was launched, there were other factors which prompted the re-organisation. In April 1989 Paxman had sold its Filtration business which previously took up a large amount of space for building rotary vacuum filters. The space which was freed up allowed more scope for rationalisation. More importantly, it was believed the costs of running the Hythe Hill site could be cut considerably by rationalisation and re-organisation. Expense could be saved on the heating, lighting, maintenance and business rates of unused and under-utilised buildings. It was estimated that with rationalisation about one third of the covered area of the Works could be vacated and made available for demolition.

By mid- to late-1989 plans had been laid for creating a single Parts Manufacturing Department (PMD) which would bring all the site's machining activities under one roof. The thinking behind the plan was that such a Department would be easier to manage than six separate shops in different buildings, there would be less movement of materials, machine tool maintenance fitters could be used more effectively, and consolidation would free up space for other rationalisations such as that of the various Stores. One should add that the plan would not have been feasible without the advanced capabilities of new machine tools; in some cases enabling one machine to replace two or three conventional machines. The new PMD was to be located in the area occupied by the large No 3 general machining shop and No 5 crankcase bay.

Alan Creasey was appointed Manufacturing Development Manager to oversee this very major project. Alan had joined the Company many years beforehand as a technician apprentice and even at that stage demonstrated great promise, winning various prizes. He subsequently gained an enormous depth of production engineering knowledge so was ideally qualified to head up the project. Also heavily involved in the implementation of these changes was John Pyle, in his capacity as Production Engineering Manager and Alan Barnes who was in charge of the Works & Plant Department, and the members of their respective departments. Alan Creasey wrote several articles in issues of Paxman World between 1989 and 1992 explaining the changes and reporting on progress (see issues 21 to 27 inclusive).

By the summer of 1990 the whole Fabrication Department, previously spread over five shops, had been moved into the former Deltic Shop, a building attached to the outside corner of No 5 machine shop. Included in the move was a large hydraulic press which had originally been installed more than a hundred years before. The crankshaft overhaul facility had been moved out of No 1 and successfully transferred to No 3, adjacent to the Nitriding Plant. Also from No 1, the large Droop & Rein Plano Milling Machine had been moved to No 5 for work on crankcase overhauls. A new Medical Centre was being fitted out within part of the former Metallurgical Laboratory; the Met Lab itself having been relocated in the West Building. Work on a new single status Staff Restaurant was due to commence during the 1990 summer factory shutdown. The Restaurant was to replace the Works Canteen and the Senior Managers' Dining Room. By the end of the year both the new Medical Centre and Staff Restaurant were operational.

By Spring 1991 the new Mazak FMS (Flexible Manufacturing System) palletised CNC machining centre for manufacturing cylinder heads was being installed in the PMD and about to be commissioned. This was to be coupled with the progressive transfer of cylinder head machining from No 6 to the PMD. Moves to bring together Machine Shops 1, 2 and 6 were in the final stages of planning. Consolidation of these three shops into the PMD would allow scope for further reorganisation. Goods Inwards and Production Stores could be brought under the same roof as the Spares Stores and Spares Despatch.

Considerable further progress had been made by Christmas 1991. Machines for the manufacture of cylinder liners which had been transferred from No 1 to the PMD included two external cylindrical grinders, two internal grinders, a long bed combination turret lathe and the Mazak turning centre. The Mazak FMS installed in the spring was 'functioning extremely well and producing cylinder heads to the quality standards envisaged'. New Tool Stores and Tool Service areas were being set up in the old No 4 shop. The massive tool store in No 3 was to be removed to make space for the cleaning and water test facilities to be moved into the PMD from the old No 2 Erecting Shop building. 80% of No 6 machine shop had been cleared and the space made available was soon to be prepared for its new role as Goods Inwards and the Production Stores. The Fritz Werner Duplex Mill from No 6 had been installed in the PMD, opposite the site of the old 'Crystal Palace'. New cylinder head processing and assembly facilities were being set up in a part of the old Fabrication Shop which had been redeveloped to make it an integral part of the PMD. In October 1991 Paxman had placed its highest value purchase order ever, at £2 million, for the Kolb Crankcase Machining Cell. This was to be purpose built for the machining of VP185 and Valenta crankcases.

By the summer of 1992 rationalisation of the machine shops and the stores complexes was nearly complete. Transfer of the connecting rod machining facility from No 2 to the PMD was to take place gradually and was expected to be completed by the end of the summer factory shutdown. Authorisation had been granted for the purchase of the Hüller Hille, representing an investment of £800,000, for machining connecting rods and cylinder heads. It was to replace the two Bohle W2 machining centres in No 2 which were not included in the transfer to the PMD. The old tool store in No 3 had been completely demolished and the setting up of the Tool Store and Tool Service facility in the old No 4 shop had been completed. The cylinder head operations previously carried out in No 6 had been totally transferred to the PMD. The vacated space was now occupied by the Production Stores, Goods Inwards and Goods In Inspection which had been transferred from the south east corner of the site.There was now a complete Product Stores complex under one roof, comprising Goods Inwards, Goods In Inspection, Spares, MOD and Bond Stores, Production and Consumables Stores, Spares Despatch and Kit Marshalling (for engine assembly). The old Works Engineers building in the middle of the yard, opposite Standard Road Gate, had been demolished.

In the Winter 1992 edition of Paxman World Will Pavry wrote 'We have not slackened the pace of development in the plant or in new engines and I believe that we will be in the fortunate position of having one of the best manufacturing facilities for diesel engines with one of the best product ranges by the middle of next year'. That was a fair claim as the mammoth task of implementing a most ambitious rationalisation scheme was brought to a successful conclusion with the commissioning of the Hüller Hille and the Kolb during 1993.

Descriptions of the main machine tools installed in the machine shops can be found lower down this page.

The End of Manufacturing at Colchester

In February 2003 MAN B&W Diesel Ltd announced that manufacture of the VP185 engine was to be transferred from Colchester to Stockport later in the year. By the end of October some of the machine tools had been relocated to Stockport and most of the machine shop staff had been released. During November the only remaining activities at Colchester were machining of VP185 crankcases and some finishing operations on con-rods. To support the Repair & Overhaul function, which remains at Colchester, a small machining facility was set up in the South Shop. Those machine tools which were no longer required on either site were auctioned off at Standard Works on 2nd December 2003. This marked the end of Paxman's proud 138 year history of manufacturing at Colchester and 127 years of manufacturing at Standard Works on Hythe Hill.

Looking north towards Hythe Hill. In the foreground is the castings compound with Goods Inwards and the main Stores complex behind. To the right of the Stores is the old office block, standing out from the old machine shops on the right of the photograph. By the middle of 2006 all the buildings visible in this picture had been demolished.

The last VP185 crankcase being machined at Standard Works on the Kolb in 2003.

Key Machine Tools

Below are details of some of the key machines to be found in Paxman's machine shops in the two decades before manufacturing ceased at Colchester in November 2003. They include most of the machines purchased and installed as part of the major rationalisation and re-organisation of the machine shops which took place between late 1989 and 1993. The listing is by no means complete but gives a good indication of the capital investment involved, the range of machining facilities installed, and the types of work undertaken.

Where shown below, the cost is that at the time of purchase with no allowance for inflation.

Giddings and Lewis 70Dp4T Spindle Borer

MANUFACTURER: Giddings and Lewis
DATE INSTALLED: 1974
COST: £70,000 (estimate)
DESCRIPTION: Horizontal Spindle Borer with NC (Numerical Control) dial in positioning system.
MAIN DUTIES: Machining spares crankcases.
NOTES: After closure of the machine shops in November 2003, this machine was retained at Colchester and relocated for use in the overhauls business. Horizontal boring requires a high level of craft skills from the operator, particularly in setting up and securing a work piece accurately and firmly in position before commencement of boring.

Warner & Swasey 1SC Bar & Chucking Lathes

MANUFACTURER: Warner & Swasey, Halifax.
DATE INSTALLED: 1978?
COST: £70,000 (estimate)
DESCRIPTION: CNC (Computer Numerical Control) bar & chucking lathe with combination chuck and automatic bar feed.
MAIN DUTIES: Turning small components such as fasteners (bolts and studs).
NOTES: These machines were very productive and remained in use up to the early 1990s. They were disposed of as Paxman progressively implemented a policy of buying out small components rather than manufacturing them in-house.

Bohle W2 Horizontal Spindle Machining Centres

MANUFACTURER: Reinhard Bohle, Germany
DATE INSTALLED: 1979
COST: £300,000
DESCRIPTION: CNC Horizontal Spindle Machining Centres with automatic toolchange and pallet shuttle.
MAIN DUTIES: Machining con-rods and bearing blocks.
NOTES: Two of these machines were installed in No 2 Machine Shop. They produced a great deal of work throughout their lives before being retired towards the end of 1995. For a time one was run in parallel with the Hüller Hille (see below), working on spares.

Bohle FP120/2S Plano Vertical/Horizontal CNC Machining Centre

MANUFACTURER: Ingersoll-Bohle
DATE INSTALLED: 1981
COST: £700,000
DESCRIPTION: Vertical/Horizontal CNC Machining Centre
MAIN DUTIES: Machining Valenta crankcases and, latterly, spares crankcases.
NOTES: Automatic head changing and tool changing capability allowed the machining of five sides of a crankcase at a single clamping. Fitted with Kongsberg controls and twin tables.

Kearney & Trecker Milwaukee-matic Rack Drive Moduline

MANUFACTURER: Kearney & Trecker
DATE INSTALLED: 1981
COST: £400,000
DESCRIPTION: Travelling Column CNC Machining Centre.
MAIN DUTIES: Lighter milling, drilling, and tapping operations on crankcases.
NOTES: To carry out its operations the whole machine moved in relation to the workpiece being machined. The workpiece itself did not move. Palletised jigs used with the K&T Moduline were identical to, and interchangeable with, those used on the Bohle FP120/2S Machining Centre described above.

LK Granite 80 Inspection Machine

MANUFACTURER: LK Tools
DATE INSTALLED: 1982
COST: £300,000 (estimate)
DESCRIPTION: CNC Co-ordinate Measuring Machine with Renishaw Probing System.
MAIN DUTIES: Measuring dimensions of crankcases after machining.
NOTES: The LK's measuring capacity is 4000 x 1700 x 1500 mm. All dimensions measured by the machine were recorded on printouts. These were retained with the records of each crankcase/engine, in accordance with traceability requirements of quality assurance procedures. After closure of the machine shops in November 2003, the LK was retained at Standard Works and relocated to support the overhauls business based in the South Shop.

Mazak Slant Turn ST40

MANUFACTURER: Yamazaki Machinery UK Ltd, Worcester
DATE INSTALLED: c. 1986
COST: £300,000 (estimate)
DESCRIPTION: CNC Mill/Turn Centre.
MAIN DUTIES: Machining cylinder liners.
NOTES: Called a Slant Turn because of its slant, rather than flat or vertical, bed.
This was the first of a number of Mazak machine tools purchased by Paxman. In common with all Japanese machine tools the Mazaks installed well and quickly became productive. Apparently this is because of a Japanese preference to install only well proven technologies. German machine tool manufacturers are prepared to be more innovative and adapt their technology to meet special customer requirements. In consequence the unproven aspects of German systems can take longer to install and implement.

Mazak H500/50 FMS (Flexible Manufacturing System)

MANUFACTURER: Yamazaki Machinery UK Ltd, Worcester
DATE INSTALLED: The capital sanction for purchase was approved during the first half of 1990. The FMS was commissioned in Spring/Summer 1991, at which time manufacture of cylinder heads was progressively transferred from No 6 to No 3 machine shop. By Christmas 1991 the FMS was functioning extremely well and producing cylinder heads to the quality envisaged. By then it had also been proved out on other components which gave the Company added manufacturing flexibility.
COST: £630,000
DESCRIPTION: Computer controlled machining centre, complete with tool management system, fully automatic tool changing, magazine (tool hive) with capacity for up to 160 cutting tools, and fully automatic remote pallet loading. The tool management system controlled selection and changing of the tool required for each stage of the full cycle of machining operations to be carried out on a workpiece. An important aspect of this system, essential for extended unmanned running, was tool monitoring. Cutting tools were regularly checked for wear and automatically changed if they fell outside the specified tolerance. If no suitable replacement tool was available, the machine could automatically exchange the current workpiece for another requiring different operations for which appropriate tooling was still available. Up to fifteen pallets could be loaded with items for machining and placed in racking called a pallet stocker. A stacker robot transferred each pallet and its workpiece to and from the machine as programmed to meet requirements. The combination of all these features made it feasible to load the machine with work before the end of a day shift and leave it to run unmanned through the night. Paxman used this unmanned running capability extensively for working overnight and into the weekend, particularly when machining cylinder heads, an ideal operation for this type of running.
MAIN DUTIES: The Mazak FMS became the key machine in the factory for cylinder head manufacture. It was also used for machining valve gear components such as rocker levers and cam-follower levers.

Kolb Crankcase Machining Cell

MANUFACTURER: Hermann Kolb Maschinenfabrik AG, Cologne, Germany
DATE INSTALLED: A substantial concrete foundation was laid in preparation during the summer of 1992 before parts from Germany started to arrive at Standard Works in November. The cell was then assembled on site by Kolb's personnel, prior to commissioning in Spring 1993.
COST: DM4.8 million (£2 million). The order, placed in October 1991, was the highest value purchase order ever placed by Paxman.
DESCRIPTION: The Kolb followed the cell concept already established with the Mazak FMS described above. Similar in configuration to the Bohle FP 120/2S, with automatic head and tool changing, it had additional advanced features for workpiece handling, workpiece probing, and tool monitoring. The system employed a cell control computer to organise work movement and manage cutting tools. Crankcases were mounted on 1.5 m x 3 m pallets, the latter being moved around the system using a double pallet car to exchange a fresh workpiece for a completed one.
MAIN DUTIES: All machining operations on the VP185 crankcase.
NOTES: Purpose built for machining Valenta as well as VP185 crankcases. The Kolb was transferred to the Mirrlees Blackstone factory at Stockport, Cheshire, in 2003 as part of the transfer of Paxman VP185 engine manufacture from Colchester to Stockport that year.

Hüller Hille nbh 210

MANUFACTURER: Hüller Hille GmbH, Germany
DATE INSTALLED: Authorisation to purchase was granted during the first half of 1992 with installation planned to take place before the end of the financial year ending March 1993. Implementation was completed by the summer of 1993.
COST: Installation of the Hüller Hille represented an investment of £800,000.
DESCRIPTION: Purchased to take over the work of the two Bohle W2 milling machines in No 2 Shop, its basic configuration was similar to those machines but with a larger tool holding capacity and the addition of a pallet storage and loading system. Like the Kolb, this machine had advanced tool handling and tool management systems allowing the tool magazine contents to be changed without interrupting the machining cycle.
MAIN DUTIES: Machining connecting rods and cylinder heads.

Mazak Multiplex 625

MANUFACTURER: Yamazaki Machinery UK Ltd, Worcester
DATE INSTALLED: 1993
COST: £270,000
DESCRIPTION: Highly productive CNC turning machine with twin heads and milling and drilling capability. The machine could undertake both chucking and bar work with automatic bar and billet loading via an integrated gantry robot.
MAIN DUTIES: Machining injector housings, spring carriers, push rods, adjusting screws, etc.

Conventional Machine Tools

In addition to the machine tools described above, the machine shops were equipped with a variety of older conventional tools. These included milling machines, lathes, grinders, radial drills, gun drills and planers. At least one or two machines dated from the Second World War, having been supplied to Paxman for war work.

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References
1. Paxmans' World, Issue 2, Sep/Oct 1982, p 7.
2. Paxman World, Issue 25, Christmas 1991, p 7.
3. Paxman Centenary supplement, published with Essex County Standard on 14th May 1965.
4. Paxman World, Issue 22, Summer 1990, pp 6-7.
5. Paxmans' World, Issue 2, Sep/Oct 1982, p 6.

A good overview of manufacturing technology at Paxman in the mid-1950s can be found in an extensive and well illustrated 32 page article, entitled Davey Paxman & Co Ltd Colchester - Organisation, Plant and Methods at Standard and Britannia Works, published in the July-Sept 1956 issue of British Machine Tool Engineering.

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Acknowledgements: My thanks to Brian Miller, formerly Production Engineering Manager at Paxman, for his invaluable help and comments. Brian provided some of the photographs shown on this page. Thanks also to Martin Pryke, Stan Page, John Blanc, Malcolm Frost and others for their recollections.

© Richard Carr 2005, 2006

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