by Euan Dunsmore
In essence, the process of making steel castings consists simply of pouring molten steel or steel alloy into a mould of the desired shape, dimensionally accurate and of sufficient stability to permit the steel to solidify in the exact shape of the mould cavity. Intricate and complicated castings of practically any desired shape or size, and for almost any particular application, can be made in this manner. Simple is it not?
Steel castings are primarily components to be incorporated by the client into a larger machine or piece of engineering equipment or plant. Each casting is made to order for the customer and the design of the casting is determined by that customer. The ownership of the design drawing and of the pattern, including all intellectual property rights, normally lies with the client. As a result, Menzies’s had a large warehouse for customer patterns, a drain on resources as many patterns would never be needed again, e.g. Forth Road Bridge rope-guides.
This is a follow-on from my previous essay where I ceased at the pour of liquid steel from arc furnace into the ladle. This essay describes how the castings from that pour go through a series of processes before being despatched to the customer. The foundry manager was Mr. Bob Blake and Works director Mr. Jimmy Paul. The moulding shops were managed by Bill Trotter along with the Pringle brothers as foremen. The workforce in my time included men who had fought in both World Wars and the Korean conflict, always quiet and seldom with smiles. One of the machinists had been a German POW, a boy really when he had been captured but now settled down in Bathgate. There were a few who would now be described as ‘special needs’ but were fully competent at the works they did, generally simple labouring.
Large castings may take the best part of a week to cool down before being broken out of the mould whilst the boys’ hutch- and bogie-wheel castings were broken out by the end of the shift. A completely new system of breakout and sand-reclaim was instituted requiring buried conveyors and several shake-out stations where the mould was placed on large vibratory tables and shaken until the sand broke away leaving the casting and moulding boxes. Before removing the feeder and risers either dry- or wet-blasting was carried out to remove cores and clean up surfaces of burnt-on sand. Regardless of how effective the mould preparation was, some sand might be burnt on. Conditions inside the mould, regardless of the care in design and moulding practices, are severe with liquid steel swirling in the mould before settling down to freeze.
The heavy dressing shop had the wet-blast room, a dark, warm sort of hell where men dressed up in rubber suits and helmets before wielding a high-pressure hose to remove, whilst the casting was still warm, as much as possible of all the moulding sand clinging on. After this the castings are passed on to the men who used oxy-acetylene torches to remove feeders and risers. Risers are the large reservoirs of liquid steel needed to counteract the shrinkage from liquid to steel. Without them castings will have internal shrinkage defects. Complex castings will have several risers and in large castings perhaps two feeders and there would be fins at the joint face between the cope and drag1 parts of the mould. Dressers, the men who burn and clean the castings, are hard-men indeed doing a dirty job with pneumatic hammers and heavy-duty grinding machines both portable and mounted These men developed full body muscles for sure. Heroes indeed as were all the foundry workers I met. Mr. McMurdo was the manager of these men along with a few foremen. Fettling is the English description of the work.
After the heavy dressing, castings were moved over to the light-dressing shop, a place where the noise was excruciating from the pneumatic hammers. Each man had a set of chisels to cut or dig or peen as required: mainly flat chisel for fins and burnt-on sand, half-round to dig out, extra-long to get deep inside a bore, etc. They would require sharpening and eventual replacement. The Blacksmith shop looked after the chisels by hardening them as and when they needed refurbishment.
There were several machines for shot-blasting after manual dressing where the castings on a revolving table or a tumbler mechanism were subjected to a hail of steel shot for several minutes to remove all sand and disguise the scars from dressing. Another noisy process. Some castings might show large surface defects or hot tears that were removed by manual gouging before being replaced with weld metal. Several booths for this activity lined the far wall. More noise and sparky light.
There were a few heat treatments given to castings depending on the material specification: annealing, normalising, quench in oils or water, and tempering. Several furnaces were dedicated to this, coal-, and gas-fired at first with electric in the new advanced quench system. Annealing is done by soaking at high temperature for a number of hours and leaving to cool down slowly in the furnace. Normalising, also at high temperature, and on completion of the soak the charge was brought out to cool in still air. The main furnace had a double, movable hearth allowing for a fresh charge to be treated immediately the previous charge was brought out to cool down to room temperature. The furnaces were fully automatically temperature controlled by Honeywell controllers of various types. As an aside, the pneumatic versions were a maze of plumbing with a windy pump in the corner of the cabinet. I found out that by applying just the right amount of force to shut the cabinet door it would unstick whatever valve or orifice was causing the problem and return to full working order.
A new oil quench facility was established and I had the honour of making the first quench. When on night shift as the duty chemist, there were quiet intervals between casts and the day shift were quite aware of this leaving various little notes for jobs to be done.
A note was left: quench cycle ends at 03:15, be there and quench the load. There had been problems with installation requiring a freezing of the sub-soil to allow for building the large quench tank. When they dug the hole, it was full of water the following morning, Menzies’s was built on the top of a bog. But now it was installed and working so to the installation and a quick learning of the charging machinery for drawing out a skid-load of castings at 925oC and transporting them a few yards to the quench tank and then lowering the five-ton load down into 10,000 gallons of finest whale oil with a great fizz and fumes as the load was raised and lowered to ensure rapid cooling until the castings were black. Things were different then. Whales were slaughtered as, unfortunately, their oil was perfect for this purpose. It took several years of experiment to find the perfect replacement from the mineral oil industry.
In the corner of the light dressing shop was a large surface table where castings were checked against drawings for dimensions, and geometry. Geometry issues were usually the result of twisting or bending either from the mould or heat treatment. Correction lay in the hands of a blacksmith.
There was a line of blacksmiths in a shop where at one time mining hutches were fully fabricated but now only the wheels were pressed onto axles. A line of small hammers and shears were part of the shop’s tool kit. But here was where castings were straightened by careful arrangement and application of pressure. Sometimes the pressure was by bomb and gravity. The blacksmith would determine the spot to be hit and raise a large bomb-shaped mass of steel. Warnings were made before releasing. After the wreckage of timber and steel, supports were removed and checks made to see if the casting could be declared straight, or not and another try.
As well as the ongoing improvements to machinery and processes new alloys were tried out. one such material was SG2 Iron. Normal grey cast-iron was melted and with careful additions of magnesium in the ladle the normal flake graphite was replaced by spheroidal globules resulting in a ductile rather than brittle cast iron. With the cooperation of one of the earthmoving machinery clients, Euclid or Terex, a trial was arranged for a large wheel hub to be made and tested. The trial was conducted in the blacksmith’s shop. People watched from behind pillars and other safe places as the largest and heaviest bomb was raised to the greatest height before plunging down to the target. It stotted, boing, in one direction and the hub another, along with a scattering of folk to the outer limits of the shop. It was a success, no breakage and part from a flat spot no deformation. There could be fun working in the foundry!
FL Smidt is one of the world’s greatest makers of cement kilns. These can be several hundred yards long fired at one end and gently turning round and round at a tilt. Ground rock (limestone and shale), almost powder, poured into one end passing through a fierce flame with cement dust coming out the other. Such a large piece of machinery needs strong heavy rotating supports and the NBSF made them all the time I was there, almost one per month or so. The rollers driven or free rotation would be about a yard across the face and the same in diameter with a central 12-inch hole for the shaft. The shafts were bought-in forgings and we machined both parts and then shrink-fitted the shaft into the roller by heating the roller in a furnace to somewhere about 350oC and dropping the cold shaft into the hole and leaving it to cool. There was a great deal of careful setting up with the shaft held in position waiting for the roller coming out of the furnace supported high enough for the shaft to fit to length as well as shrink. All went well until the one time the crane brake refused to let go with the shaft partly into the hole. Panic. One of the Glasgow forges said they could press the stuck shaft out, no bother. Roller and shaft came back, still fast united with a pancake type The shaft was machined out and a new one purchased.
Before the days of computer analysis programmes, castings were designed essentially by hand and eye and experience. Calculations were basic but certain other basics were well known, a heavy section separated from another by a thin section required careful positioning of feeders, risers and chills with as few compromises as possible, sharp corners replaced by shallow radii, etc. Cooling down in the mould or too-soon release from the mould would raise stresses resulting in hot tears or cold cracks, poor feeding shown by excessive internal shrinkage or sand could be burned on. The IBF3 issued a book of one hundred and fourteen pages of illustrations of the defects that could be found in castings from all processes.
From a life time in the world of materials:
Materials are collections of defects
Acceptable material is an accidental or organised collection of non-consequential defects
Scrap material in an unfortunate collection of defects
A defect is an imperfection of finite size and distribution, sometimes significant, sometimes irrelevant.
Acceptance for Quality Control
Acceptance for Fitness for purpose.
Depending on the client and industry, castings were subjected to non-destructive testing to look for and determine defects and how many, or how bad. We metallurgists were tasked to look for defects both surface and buried: Visual, Magnetic Particle Inspection (MPI), Radiography, Liquid Penetrant Inspection (LPI) and Ultrasonic Testing (UT). Most of the training was ‘on the job’. An evening-class course was arranged for us all to attend Heriot-Watt College in Chambers Street in Edinburgh.
We were allocated a film badge and radiation monitor early in the apprentice induction period. The film badge worn on the lapel was sent to the radiation authority every month. The monitor I checked after every excursion into the booth where castings were exposed to open-source radiography. We used a low-strength Cobalt-60 source needing hours of exposure to find internal defects, usually shrinkage or sand inclusions or porosity. We became adept at setting up films and castings and reducing our exposure time to seconds before and after the process. The films were processed and viewed in the laboratory dark room.
The radiation booth was open-topped close to the blacksmiths’ and fitting shop and a light dressing shop but with heavy concrete walls. A survey was done by the authorities to check safety as there was a manned overhead crane. All was well.
MPI is a messy business consisting of imposing a magnetic field into the surface and spraying copious amounts of paraffin-based magnetic ink looking for surface defects under a UV lamp. Being portable, most departments saw the brown-coated metallurgists bending over castings and, wielding a yellow crayon, marking defects, mainly crack-like hot tears, healed-shrinkage or stress cracks.
LPI is a similar messy business used mainly on non-magnetic alloys and apart from visual inspection probably the oldest of the systems and will find any surface- breaking defect. The surface is thoroughly cleaned before being dowsed in a mobile rad or UV type dye. Left for a determined period it is cleaned off, dried and then covered in white powder. Surface-breaking defects show up very well.
UT was a brand-new system on the 50’s and when first introduced the equipment surfaced in the physical laboratory with the great interest of the bosses including the two senior metallurgists back from their two years National Service, Willie Blackadder, and Jim Thompson. We, the apprentices, were not included. I would have been for the same Service but it was abolished the month I turned eighteen.
Again, a nightshift with instructions to check a large machined piston-head for a Sulzer marine diesel engine. This was the first time I had switched on the machine or handled any of the various probes along with a curiously shaped piece of steel I later found out was for calibration purposes. Hours were spent fiddling until some sort of sense could be made of the signals on the screen. I spent an afternoon in the public library checking the physics of sound. The second night I had another go. Results, who knows. As an aside, most industries were fiddling with the system for some years sorting out standards and specifications. Eventually a Sulzer specification arrived with a plethora of instructions and acceptable defect levels.
Castings for pressure control and pressure retention often required the quality to be monitored by third party inspectors such as Lloyds Register, Royal Navy, AEI,4 DNV,5 etc and as such were frequent visitors to the laboratory, test-house and inspection areas. We had a clerk, Jimmy Lees who prepared, in perfect copperplate writing, the various certificates of test and inspection for review by the third-party inspectors. We accompanied these inspectors to the test-house for them to witness mechanical tests on coupons6 from the appropriate heat, and carried out MPI at their request.
A back log of upgrading and repairs became an issue and soon after my HNC I was deposed to a small dressing shop next to the radiographic booth to supervise the work as well as carry out inspections and work with the client inspectors. Jackie McLean was the chargehand who allocated the work to the eight or nine dressers, grinders and welders who dug out the defects and dressed the welds. He was a pigeon fancier as were many men at that time. This work was done after the heat treatment and required a weld-stress relief after the casting was pronounced good. For some of the castings, mainly pressure-relief and safety valves all defects were recorded by photography and sent for approval before welding. I spent a deal of time taking and processing these with sometimes eight copies needed.
Tommy Ditchburn was one of the men in Ward 10 and he was not bothered by the appalling noise of pneumatic hammers on steel. He was completely deaf from childhood. We only had some woolly stuff to insert in our ears. I could sign but not lip read. Every department had overhead cranes and we all knew the simple signs.
I had noticed that castings being returned for minor repairs had not looked good with shiny scars where grinding had been carried out after welding or with obvious chisel marks. I made it an issue that all castings from Ward 10, as my shop was nicknamed, be sent for grit blasting on the point that ‘if it looks good it must be good’.
Castings I remember are many. We were at the forefront of developing cast steel fins for ships’ stabilising systems. Admiralty inspectors looked after them as well as a variety of castings for MacTaggart Scott. Cylinder covers and liners, piston heads, bearing covers and crankshaft sections for B & W7 and Sulzer diesel engines were on the go all the time as the Clyde was busy building ships for the world. We made rope guides for the new Forth Road bridge and the machine-shop bored several hundred 4” holes in dozens of weight guide blocks to hold, guide and anchor the wire ropes. Pelton runners for Swiss run-of-stream power stations became a horror for me in the repair shop. Made from 13% Chromium steel they were of thin section and prone to stress cracking, a lot. I also have memories of crack-detecting hundreds of axles for earthmoving machines and crawling into stern tubes or UT testing diesel engine balance castings for B & W diesels.
Servicing all the equipment and gear needed a contingent of fitters and electricians. The fitting-shop was run by Mr. Livingston and Jimmy Wilson, a friend from my first day at school. Here he saw out his apprenticeship. The full works had a pneumatic ring-main supplying all the pneumatic hangers and rammers from a large room with several large piston machines working day and night to supply air.
After seven years in Menzies’s, it was time to move on and in 1964 and I left for another metal altogether and a different process. It was a time of full work and the Menzies brothers ensured their foundry was up to date on all fronts with new improvements coming every year I was there. The knowledge from my time in the foundry was important to me in my subsequent career in marine engineering and the oil business.
Euan Dunsmore, MIMMM
Mauchline, February 2026
Photographs are from the James Maude iron foundry.
Dresser with long-reach chisel working on a casting. Recent, as he has ear defenders.
- Cope – upper part of mould cavity; drag – lower part of mould cavity.
- Spheroidal Graphite iron
- Manufacturer of seamless steel pipes
- Company with a wide range of products including those for boilers and heating systems
- Quality assurance and risk management company
- Test coupons – representative samples of main product (e.g. flat strips, discs, rods). They are tested to evaluate properties of main product.
- Burmeister and Wain diesel engines
Bathgate Old Times 