STEAM ENGINES AND WATERWHEELS

[Stanley]

Notice that I said that a banked boiler held pressure all night. This didn't happen by accident. About 45 minutes before finishing time John Plummer started his shut down process for the night. He started by setting his feed pumps on and increasing the firing rate to keep the pressure up while he was filling the boiler to a level just below the top nut on the water gauge. As this was going on he ashed out so we had a clean furnace in the morning. As this was going on the pressure would rise but this was no problem for me, running the engine.
When he had his water up and the pressure as high as he could get it without the safety valve lifting, the coal in the hoppers of the automatic stokers ran out. This was of course no accident! At this point John opened up the dampers to get maxi=mum draught, stopped the stokers and spread out the coal in each furnace to give an even bed. He burned both furnaces off until there was only a small amount of fire in each. At that point he almost completely closed his dampers and pushed what fire was left to the back of the bars. Then he shovelled in thirty shovel full of coal evenly into each furnace covering the bars. The idea was that the fire at the back slowly crept forwards through the green coal during the night. At this point he made the final adjustment to his dampers, just enough draught to keep the smoke moving forward into the fire. Then he shut the check valve on the feed-water main down tight to make sure there was no chance of leakage back into the main, shut the boiler house door and went home 15 minutes before engine stopping time. (I always booked him his full time).
For the next 15 minutes the engine ran the mill with no fire in the boiler and gradually dropped the pressure to about 120psi. The beauty of this system was that when I came in first thing, before John had woken the boiler up, the pressure had recovered to 140psi and there would be well over half a glass of water in the boiler even though the warmer had been on on the engine all night bleeding a whisper of steam into the cylinders to keep the temperature up.

[Stanley]

Unless we were in early in winter to fire the boiler for shed heating (Many a time from midnight onwards, John and I took turns at this) we both came in 30 minutes before starting time. I got the engine ready for starting and John woke his fires up and started firing for the start. The boiler always had just over half a glass of water and pressure very close to the 140psi we needed for a start. At starting time he had a boiler full of water, good fires in and the pressure just below blowing off at 160psi. This was a very skilled operation and he was brilliant at it. As soon as the engine started he adjusted the pressure until he had his magic 140psi. This was perfect firing and made my job so easy....



Looms at night in the weaving shed on a very cold morning in winter. The job was to get the shed to 50F at starting time and 55F half an hour later. We couldn't always achieve this....

[Stanley]

The advent of the heating season was bad news for us. On a really frosty night we had to start firing for heating at midnight. John and I used to have a council of war each afternoon and decide on when to come in and who would do it. It was a cold lonely job coming in to a cold shed in the middle of the night, many a time just as people were going home to bad after a night out! Our shed heating was simply ranges of 2" steam piping throughout the mill and we put steam in at full boiler pressure. The mains all terminated in the boiler house and the hot condensate was piped direct to the hot well where the feed pumps picked it up and returned it to the boiler as feed water. It was pure treated water and hot enough to make the heat in it worth re-using. Tomorrow I'll go through the whole process.
Incidentally, one of the many penalties that mills suffered when they electrified was that often this meant that condensate return from heating was neglected. Johnny made quite a lot of money on advising mills about this after electrification when many found that they were burning more coal with the engine stopped than they were when it was going and of course they had the cost of electricity on top.

[Stanley]

It's a bitterly cold morning and you are in at midnight. Your task is to get the shed to 50F for starting time! First job was to open the engine and boiler house and switch the lights on. Then into the cellar and set the pumps so that as the water in the hot well rose the float switch automatically kicked in and fed it back into the boiler. As you passed across the front of the boiler you opened the check valve on the feed main which has been shut down all night to prevent leakage and opened the dampers to waken the banked fires up. Then you went on the Lancashire boiler top to the manifold on the wall where the steam feed went into the heating ranges and the condensate returns came back to be piped back to the hot well for returning to the boiler. First you cracked the separate steam valves to each circuit. Remember that your boiler has 140psi as it has been banked all night. Steam started into the pipe runs and crackled as it hit any condensate left in there. Then you opened the by-passes on the end of each pipe run to let the trapped, cold condensate easy passage to the hot well.
You had a fair idea how long it took for the trickle of steam to clear the pipe runs, it wasn't fast because this was where you did the most damage to the heating pipes by water hammer. You knew you had time to go down on the firing floor, open up the furnaces and drag the hot coals back to the front onto the coking plates. They were burning white hot because you had opened the dampers as you went up onto the boiler. Then fill the hoppers on the stoker which had been left empty all night because it was possible for the coal to ignite in the night and the last thing you wanted was burning coal in the hoppers! If you were lucky there was enough coal in the bunker to cover the auger bottom, if not you jumped in and started shovelling! Then set the stokers on a whatever you judged was the right feed, adjust the dampers and back up onto the top just in time to feel the shortest pipe run by pass pipe heating up as raw steam got back to it. As soon as you had a hot by-pass you closed the by pass valve and the steam trap took over, keeping the steam in but letting the hot condensate out into the manifold.
You stayed there nursing the other feeds until all were running clear and all the by passes were shut. Then down to the firing floor, top the hoppers up, adjust the stokers and dampers if necessary and off up into the engine house to brew up. The first stage was accomplished, you had a boiler that was steaming and heat going into the shed. you kept your ears open to check that the feed pump was kicking in as the condensate came back. I can still hear those pumps now, the Pearn running constantly and the Big B&P kicking in when needed. The ringing of the gears was your companion and assurance that the system was working!

[Stanley]

Once you were settled in and had your first pot of tea of the day down you it was time for a quick check in the cellar to make sure all was well with the pumps. Then into the boiler house, check on the fires and dampers, make any necessary adjustments, check that you were holding your water level in the boiler and finally top the hoppers on the stoker up. Time now for a trip round the mill to check on everything. On the way past the large distributor panel for the alternator and electric you switched on the pilot lights in the mill. Theses were fluorescent lamps on a common ring main and were sited at strategic points throughout the shed to give just enough light to see by. You needed a torch as well for things like checking thermometers.
Under the Factory Acts you were forced to have thermometers in every work area and for the next few hours they were the focus of your attention. The shed was the worst area to warm up so once you had done an initial full inspection you concentrated on that. If the shed temperature was rising the rest of the mill was OK. On a very cold morning, especially after the weekend shut down, the temperature could be below 40F. Any heat you put in rose to the ceiling and forced cold air down so it wasn't unusual to see the thermometers dropping for the first hour or so despite live steam in the pipe ranges. Very dispiriting!
The shed was an eerie place. Normally so noisy but you could hear every small noise as the heat expanded pipes and metal artefacts. If everything was OK it was time to check the boiler again and then if you had any sense, have twenty minutes asleep in the arm chair in the engine house! You got used to being able to cat nap, essential to survival when you were doing long hours like this. Then the same routine again, check the temperature in the shed and the condition of the boiler. One sound I can hear in my head now is what you heard as you walked across the yard. On a frosty morning it was calm and quiet and all you could hear was the ringing of the gears on the feed pumps in the cellar and the whine of the hydraulic drives to the gearboxes of the two Proctor stokers accompanied by the groan and squeaking of the fire bars as the cams drove them in and out individually to move the fires down the furnace. Remember they ran dry because of the heat and the noise they made was unmistakeable. If you were lucky you started to see a slow rise in the shed temperature but it was never fast enough!



Perfect! Full hoppers and you can see the glow of the fire on the coking plates through the holes in the furnace doors. The gauge is on 140psi, all is well!

[Stanley]

The reason the weaving shed was so cold was that half the roof was single thickness panes of glass and the other half was slates with no insulation beyond a lath and plaster skim in the underside. Any heat you put in the shed rose to the top and warmed the sparrows! On a cold morning even after 7 hours of steaming you sometimes didn't reach the magic figure of 50F. The weavers were quite understanding because they knew that we were doing our best for them but even so it was miserable for them coming into a cold shed. The only advantage we had was that once we started driving the shed, the belts circulated the air and brought the warm air down from the roof, it was quite possible for the temperature at loom height to rise five degrees in the first half hour or so.
When we started running on a cold morning we often had another problem. The tape sizing machines upstairs were heavy users at the best of times and if they both decided to boil size first thing we had to stop steaming the shed because the boiler simp0ly couldn't cope with demand even though John was pushing it as hard as he could. Things got even worse if it was a dark morning and we needed the shed lights as well. At that point John would have to employ his last strategy. Stop the feed pumps and allow the water level to fall in the boiler. In the early years before I installed the big B&P feed pump this gave us another problem because the old feed system could only cope with demand if the pumps ran continually all day and even then we were losing ground.



1977, we were struggling, fog, frost, shed light and bad draught. This was before I had the advantage of John and the new feed pump.

[Stanley]

Hot summers could bring their own problems. 1976 was an exceptional summer and the temperature in the shed slowly built up even with all the doors open. I soon got evidence that it was the hottest since the mill was built and opened in 1920 because I was called into the shed one day to investigate a squealing noise at the end of the shed furthest from the main lineshaft. The cross shafts were 250 feet long and what had happened was that they had expanded so much that the ends of three of the shafts were trying to bore their way through the shed wall!This was the first time this had ever happened and all I could do was put thick oil on and keep running once I was sure that the expansion wasn't affecting the lineshaft. Once we closed John and I had to go in the shed and hacksaw a couple of inches off each of the shafts. They were almost 2" at the ends and it was hot hard work!

[Stanley]

Another problem that arose was that the timbers supporting the glass roof of the ladies toilets shrank so much that there was a danger of the roof falling in. I had to repair it during the day while it was being used and I have to report that my education advanced significantly while I was doing it!

[Stanley]

In hot weather the leather belts driving the looms shrank and in effect the pick rate went up. This was a bit of a problem for the weavers because the dryer a warp is, the more likely breakages are. Billy Lambert kept me on track and I used to follow his cue and lower the speed a bit. However, this slight lowering of speed caused me problems in other areas particularly the alternator which supplied most of the electricity in the mill once the engine was running.
The mains feed into the mill was never designed to provide enough power to power all the systems in the mill. It only powered the engine and boiler house, the office and the pilot lights. When we started in the morning we were switched over to the mains and as soon as the engine started I threw the switch that put all systems on the alternator, We didn't need mains power to run the mill. This was a great advantage when we entered the era of power cuts, many people were puzzled by the fact that when power was off in the town, Bancroft's lights were still on and the mill running. However, there was a problem.......

[Stanley]

We made our own electricity at Bancroft and in early October as we started to come into the heating season the load on the boiler went up. I started to get complaints from Fred Roberts about there not being enough power to run the Barber knotting machine. This ran on 110 volts DC and any drop in the alternator supply made a big difference to his voltage level. It ran OK off the mains but wouldn’t perform off the engine. His version of it was that I was frightened of the engine and was running it too slow! Not surprisingly this got my back up and I told him that things were no different than they had been for the last twenty years, there was a fault somewhere and I would find it.
I had a fair idea that there was a fault because the electronic adding machine in the office wouldn’t work properly off engine power so I suspected the voltage was down. According to the instruments on the big switch board in the engine house all was OK but I spent £85 on a heavy duty Avometer and did some tests of my own. I found that instead of turning out 450 volts on three phase we were only doing 390, the voltmeter on the board was way out. I tried altering the resistance to the exciter but couldn’t get more than 410 volts so I sent for the sparks and got them to alter the permanent resistances in the circuit. That did the trick! We could get 450 volts now with ease.



The alternator driven off the lineshaft. Once the resistances were sorted out it gave its full output of 450 volts AC.

Jim came down and told me Fred Roberts was in a right mess. He couldn’t control the knotting machine, it was going too fast. I went up and informed Fred that I had sorted out the problem at my end, he was now on 450 volts as per design and any problems he had were his own, go to it Fred! He never spoke to me again as long as the mill ran, this did not cause me any problems! The calculator in the office was working OK as well.

[Stanley]

John Burlison sent me this pic of a Dan Adamson superheater element at the back of one of their Lancashire boilers.



A NEW SUPERHEATER

November 3rd 1923

The textile industry is considerably better than the average so far as utilisation of the benefits of superheating are concerned, although why steam users in general in Great Britain should so largely neglect the superheater is not easy to understand. The advantages of superheating are of course obvious, both in throughly drying the steam so as to reduce the condensation losses in the steam pipe circuits and in improving the efficiency of the steam engine.
In the case of large cotton mill engine the benefits of superheating are somewhat greater than in a turbine, because of the larger area exposed to the cooling air and the consequent increase in loss of heat. The net saving in the coal bill due to superheating can roughly be stated in the case of a turbine as 100 deg. F. being equivalent to a reduction in the coal bill of about 7½ per cent., while 200 deg. F. superheat results in about 12 per cent. saving. In the case of large reciprocating cotton mill engines 100 deg. F. will reduce the steam consumption at the stop valve 12 per cent., corresponding to about 9 per cent. net saving in the coal bill, while at 200 deg. F. the reduction in the steam consumption is 22 per cent. and in the coal bill about 16 per cent.
In connection with superheating, it is interesting to note that Messrs. Daniel Adamson and Co., Ltd., the well known engineers of Dukinfield, near Manchester, have now brought out a new sectional type of their well known accumulator superheater.
In designing a superheater the object is to increase the rapidity of the heat transfer as much as possible, so that theoretically the best principle would be a large number of very small bore tubes so as to split the steam up into thin streams. This is of course impossible in practice, since such tubes would rapidly warp and burn out, besides being quicly choked with sediment from the steam. Consequently most superheaters are a compromise, say a 1¼ in. to 1½ in. tube, which gives sufficient strength, but correspondingly reduced efficiency of heat transfer. In the Adamson superheater, as is well known, the high ingenious principle is adopted of a wide tube with a central gilled hollow cast iron core, which splits the stream into 5 thin layers, giving increased heat transmission combined with great strength.
In the new "A.B. Sectional" modification, the loops or superheater tubes are made from solid drawn weldless mild steel, being 4in. outside diameter and ¼ in. thick, suspended as usual in the flames and hot gases in the boiler downtake and connected to 4 in. diameter nipples on the under part of the top headers by means of a special screwed union joint. The ends of the superheat tubes are fitted with heavy octagonal steel nuts, screwed to suit the header nipples, and when thse nuts are screwed up the ends of the superheater tubes, which have been staved out by special tools, are forced up against the nipples, a steam-tight joint being made by means of an intervening soft corrugated copper joint ring. In this way the screw threads are entirely protected from the action of the hot gases, while the tubes are also staggered so as both to increase the efficiency of the heat transfer and reduce the resistance to the passage of the gases.
The two headers are circular, being made from 6 in. bore solid drawn steel tubing, having 4 in. screwed nipples welded on underneath, as already mentioned, which have also been made from solid drawn steel tubing. Both headers are fitted with flanges bolted on at each end, and these headers also include two 6 in. branches for inlet and outlet connections, which are welded on as usual. This one header is also provided with a mild steel steam-tight diaphragm, to direct the steam and give a quadruple flow across the path of the downtake gases.
The whole body of the superheater, that is, the top header carrying the suspended tubes, is carried on a heavy cast iron carrier frame built up of 4 pieces (2 side and 2 end pieces) with eye bolts for lifting, which rests on the brickwork of the boiler downtake flue, and when fixed in position, the headers - projecting out of the brickwork are then provided with an outer sheet steel cover, which can then be lagged to prevent undue radiation losses to the air.

[SCG Note]
This report was written by a superheater salesman! There were good reasons why superheaters weren't widely adopted in the mills. First was the fact that old engines weren't built with super-heating in mind and the figures he gives for economies, whilst they might have been true for modern installations, are optimistic for older plants. Then there was the question of lubrication. You needed a higher specification oil for superheated steam. Many engineers didn't realise the importance of this and continued to use oil that was designed for 'wet' or saturated steam. This led to accelerated cylinder wear even in modern engines designed for the dryer steam. The effects on old style valves with extensive rubbing surfaces could be even more distressing. Even engines with drop valves had problems and in Newton's experience, needed boring more often than engines on wet steam. If the story had been as simple as the author suggests they would have been universally adopted.

[Stanley]

One side of the double tandem engine at Wellhouse Mill which ran successfully on superheated steam largely because it had a good tenter who understood the need for special oil.
One other disadvantage of superheaters I forgot to mention was that the cast iron steam ranges from the boiler to the engine weren't reliable under the increased temperature of the steam and the insurance companies enforced the recommendations of the Factory Acts in that only steel pipe and valves were suitable. This added expense was a disincentive.

[Stanley]

October 27th 1915
P Barrett chair. Minutes as read.
The bank balance was reported as £1075-17-1 in credit.
Res. That accounts be paid: Wages £70-9-1. J R Broughton £20-7-0.
Res. That Crowther's wage [engineer at CH Shed] be increased to 37/6 per week.
Res. That the cooler at CH Shed be enlarged. [The cooling system for condensing water?]
Res. That the tender of Superheater Units Ltd to supply three sets of superheaters to Butts Mill be accepted at £359-10-0. [Superheaters were a nest of pipes in the hot gases of the downtake at the back of the boiler through which steam, on its way to the engine, was passed to raise its temperature and dry it out. In theory this is a good way of improving the efficiency of a steam engine. However, the Musgrave engine was designed for lower temperature saturated steam which is far less aggressive in the cylinders. Experience later showed that lubricating technology wasn't good enough to prevent accelerated wear in cylinders and this would cause trouble at many mills. Looks like Teddy Wood chasing increased efficiency.]

This extract from the CHSC Minute Books is a window on the development of the mills.

[Stanley]

Teddy Wood was a partner at Proctor and Proctor of Burnley who acted as accountants and company secretaries for many mills. Teddy was interested in engineering and a big friend of Johnny Pickles who he used as an adviser and Johnny got a lot of work because of this. The manufacturers trusted his judgement and almost always acted on his advice.



Teddy is the man in the pin stripe suit stood next to Johnny in the bowler hat in this pic of the broken flyshaft at Victoria Mill, Earby in 1954. He was probably more responsible than any other single man in bringing modern practices into the engineering side of the industry.

[Stanley]

In case anyone is wondering why the shaft in the picture above has a hole bored through the middle of it.... In the early days of Bessemer steel shafts (and this is almost certainly a forging made from a cast Bessemer Steel ingot) there was a problem called 'piping' which was strands of impurities in the centre of the cast ingot which were elongated during forging but not eliminated. It was found that these inclusions tended to propagate cracks in the finished article and that if they were bored out this danger was largely averted. Ellenroad shaft is bored exactly like this one. modern pouring and casting methods have eliminated this and so shafts forged from cast steel today do not need this treatment.



The shaft on Ellenroad engine in 1985 before we started the refurbishment. You can see the same hole in this shaft.

[Stanley]

John Burlison sent me this more recent pic of the Ellenroad shaft end. I misled you yesterday when I said that the problem with the shafts was inclusions. This could be true but was not the main problem.
I asked my dad about 'piping' in cast steel ingots intended for forging and here's what he told me. In the early days the ingots were a simple cylindrical shape and because of their mass took a long time to cool when brought out of the mould. The exterior was set but the interior was still molten. As the metal 'froze' it shrank and by the time the core was cooling and shrinking it generated cavities as it solidified. These cavities were the problem and survived the forging process. With small sections there was a way of overcoming this which was to forge the billet flat, reheat it to forging temperature, fold it on itself and reforge. The more times you did this the more homogeneous the eventual forging. This is still the way the blanks for the finest sword blades are made. It was also commonly used for producing large cotters for steam engines.
You couldn't do this with a large ingot for a shaft so over the years the industry developed other strategies. The castings were poured into a mould which produced a tapered shape with a deeply corrugated surface and a smaller cylindrical section at each end. These smaller sections were where any inclusions ended up, the heavy ones in the bottom and the lighter ones at the top. These sections were regarded as wastrels and were eventually cut off and remelted but until that happened they were useful points to grip or sling the ingot when manipulating it under the hammer. The corrugated surface tended to exert pressure on the centre of the ingot as it cooled and minimised the formation of cavities. Father told me that when they were cooling, if a cavity formed the ingot gave out a sound like a loud crack and if you heard that as you were passing though and marked the ingot with a lump of chalk you earned a bonus.
When my NDT [Non Destructive Testing] man was testing the connecting rods on the Ellenroad engine using ultrasound he found minor lamination cracks but told me that despite the fact they were forged in the 19th century, if the CEGB got as good results with their modern turbine shafts they would be very pleased! So, while flaws have been vastly reduced they can still exist even using the most modern methods.

[Stanley]

Newton Pickles once told me something that his dad Johnny had told him. Just before the Great War in 1914 the main source of big forgings in Bessemer Steel was Krupps at Essen. They could deliver large forgings in this country cheaper than our forges could so many engines had Krupps forgings for parts like the flywheel shafts and cranks. Johnny told Newton that the surprising fact was that Krupps forgings were still available after the war started. He didn't know how they got here but said that for a couple of years they were still available.

[deebee]

Manchester's "The Arms of Krupp" is a fascinating, if lengthy insight into the skulduggery of the arms trade. The transnational nature of Krupp's business made such dealings quite easy. Krupp's patriotism was far outweighed by his drive for profit.

British shells used a licenced copy of a Krupp fuse and after the war Armstrong's received a demand for royalty payments! Astonishingly the bill was paid, although not in full. For the sake of balance a British company demanded royalties for the use by the Germans of its formula for high explosives.

db

[Tizer]

Large forgings...The UK has fallen behind (as has the USA) and the forging of massive nuclear reactors now lies in the hands of China, Russia, France and Japan. We should have kept up our technology and been up there with the best. At least there are developments in the UK and this is described on this web page: LINK

The international background to `Heavy Manufacturing of Power Plants' is explained here: LINK Note the comment: "In Europe and North America, capability to manufacture safety-related components and systems has been eroded with the scarcity of new nuclear projects since the 1980s...". I wonder what Trump will make of this: "Another development is Westinghouse going upstream and setting up factories in USA and China to produce modules for AP1000 reactors.

[Stanley]

Quite right DB, that's where I first came across the trade that continued despite the war. Have a look at the armour plate question also, it was crooked to say the least!
I agree Tiz, we have let our manufacturing industries fade away. Thatcher believed that heavy industry was old fashioned and the service industries were the future..... How wrong can you be? When the Science Museum got me in to look at the cracked air pump on the Siberia Engine I told them it was useless looking for a pattern maker capable of producing a pattern even if they could find a foundry to cast the steel body. Even if they had found the resources the cost would have been prohibitive. I advised them to get a new body fabricated and the welds ground to make it look like a casting. I think that's what they did eventually but I am not sure.

[Stanley]

John Burlison's pic of the air pump at Bancroft in 2010. An efficient air pump that gave a vacuum of about 28" of mercury was a boon to any engine tenter. Unfortunately, this one at Bancroft didn't come under this category, the best I could ever get out of it was 25". It was Robert's own design and it incorporated chambers on either side of the body which theoretically provided air cushions to smooth the action of the large bucket. In practice they didn't work like that. They ensured that there was always a large volume of air bubbles in the body of the pump which inhibited efficient operation. The best air pumps were Edward's Pumps which worked on a different principle in that the shaped bucket entered a matching depression in the bottom of the body and ensured a very positive pumping action. Johnny Pickles was a big fan of Edward's pumps and recommended fitting one at Bancroft but the management wouldn't spend the money. It was a short sighted decision because the better vacuum would have saved coal every week and soon paid for the expense of installing it. So we had to constantly nurse this pump and consider ourselves lucky if we managed 25".

[Stanley]

When I first got the engine the fact that the air pump moved constantly on its foundations bothered me but Newton told me to leave it alone. The linkage was slightly out of line and the pumps was breathing to accommodate that. If I stopped the movement, I would get faults in the linkage. I took notice and left it alone. This applied to the engine as well, I soon noticed that the cylinders moved slightly as the engine ran and Newton told me that there were only two points on each side of the engine where the bed bolts were dead tight, these were the two bolts at the front of each cylinder. All the others were slack enough to allow the bed to breathe. Apart from the movement caused by dynamic forces when the engine is running there has to be an allowance for expansion and contraction in the bed. Newton told he he had seen engine beds crack through being held down to tight. I always took notice of him!! Ernie Roberts told me that the same applied to looms in the mill. Bad running could be improved by slackening off the fastenings that held the loom frame together. One other example was John Ingoe's traction engine 'Annie'. He had all the shafting and bearings for the new gearing made by a very good local engineering firm and they did a good accurate job but the engine had problems in that it didn't run freely when being driven around. I told John it was his gear train, the bearings were too tight and when the horn plates flexed because of rough ground the shafts were binding in them. I don't think he believed me until he ran it stationary on sloping ground at one show and had major trouble with a bearing. He gave in and told me if I was so bloody clever I could cure it. So I took the main bearings out and bored them all 1/16" oversize and it ran perfectly. I told John I always remembered something my dad told me about him helping to recondition Baldwin Locos after WW1 when he worked at Vickers in Trafford Park. They refurbished the con rods and motion to usual standards but found that when they ran the locos round the bends in the yard the motion seized up. The cure was to slacken the bearings in the motion.

[Stanley]

Another place where perfection was not productive is in large plain bronze bearings. Modern lubrication operates largely on 'boundary lubrication' where the surfaces are ground perfect and oil is put in under pressure to form a boundary layer between the shaft and the shell. This is good but in a large plain bearing such as a flywheel shaft bearing that is under great pressure from the weight of the components, in the case of Ellenroad it was almost 50 tons on each bearing, a different strategy has to be employed. Enough room is left in the bearing for the oil, dropping in from the top by gravity, to form a wedge which ensured enough oil was carried under the shaft to support the weight. There was another factor. My dad told me of a case he had seen with a high speed Willan's engine running an alternator where constant overheating was cured by taking the bearing cap off and attacking the perfectly ground surface with a blacksmith's rasp! What this did was put pockets in the surface of the shaft which carried oil into the bearing. Daft as it looks, this cured what had been an intractable problem.
One of Newton's favourite sayings about bearings was that he'd rather hear them than smell them! A bit of play giving a slight knock did no damage but if a bearing got hot enough to smell you were in trouble! The problem is that as the heat builds, the shaft expands in diameter and you get a cycle of more heat, more friction and eventually complete seizure. The nicest sound in the world on a steam engine is a light click coming out of a cool bearing as the loads reversed on it. The worst is to see molten bronze coming out of a bearing...... As soon as you stop the engine the shaft seizes solid. The cure in this case is to slacken the bearing cap while the engine is running if you can and flood the bearing with oil. It doesn't hurt to play a hosepipe on it to cool it down.

[Stanley]

The pedestal bearings on the Ellenroad engine were enormous. Originally the bronze bearings were lined with Babbitt White Metal but I suspect most of that is worn out now. When I first inspected the engine I found a mains water connection close to each of the pedestals.At first I though this was simply for a hose connection but later realised that it was a bit more complicated than that. Originally there had been a copper pipe cooling coil in each of the lower reservoirs where the oil drained back to the pump which forced the oil up to the aquarium lubricator on top of the bearing.



At some time there must have been trouble with the bearing heating up when the engine was fully loaded so the cooling coils were put in to try to bring the temperature down. The strategy must have been successful because the bearings survived. Mind you, when I first took over the engine I was told that new brasses had been made for the pedestal bearings and stored in the cellar for when they were needed. They weren't there when I looked, someone had weighed them in no doubt!

[Stanley]

Bancroft chimney 'emitting dark smoke, Ringlemann scale 5' in 1977. (LINK) I have a confession to make, we never made this much smoke, I wanted a pic showing dark smoke and so got John to make some for the image!
However, a certain level of smoke, enough to attract the attention of the Council 'Nuisance Man' and get us into trouble was a common occurrence for us due to the adverse conditions we were working under so I got to be well acquainted with the factors that caused the problem.
When burning a carbon fuel such as coal or oil, various factors can combine to result in dark smoke. In order to fully understand the causes we first have to recognise that black smoke is quite simply unburnt carbon particulates coming out of the stack. The causes of it are more complicated.
Let's get one excuse out of the way immediately, bad fuel. There is no such thing, even motor tyres can be burned smoke free if the furnace is designed to burn them and properly managed. The problem is that there is no such thing as a commercial furnace which is fully efficient for every fuel. However, coal and heavy fuel oil are reasonably consistent and quite major variations in quality can be handled in a standard furnace with good maintenance and management.
We need to address another myth, the assumption that in the early days chimneys all produced dark smoke because of inefficient management. The old engineers knew how to burn coal cleanly but were almost all hard pressed and believed, erroneously, that their boilers produced more steam if they were emitting smoke. There was another surprising factor, some mill owners liked to see smoke coming out of the stack because it signalled to their rivals that they were full up with work and going flat out to cope. I have come across accounts of engineers being told to burn rubbish simply to make smoke when the mill was stopped or very lightly loaded.
In may day we were more enlightened, we had the benefit of many years of research into combustion and knew that we were making maximum steam at the lowest fuel cost when we had a light haze coming out of the stack. The question is, how did we manage that. The trick was to match the coal feed and depth of firebed with exactly the right amount of air passing through the furnace. We had Lancashire boilers with twin identical furnaces. Our Proctor Wide Ram Coking Stokers were excellent for this as long as we had sufficient load. The way they worked illustrates the correct conditions for eliminating smoke. The green coal being forced onto the firebed by the rams in the stoker hit red hot cast iron coking plates and immediately started to give off 'green smoke' which passed down through the firebox above the fire established further down. If the bed was burning white hot this gas burned and eliminated most of the carbon particulates (smoke), any that survived this because the fire wasn't hot enough mixed with the flue gas from the other furnace in the downtake. If that fire was burning hot enough, the mixing of the hot clean flue gas ignited any excess carbon for the cooler fire. This twin furnace design was adopted with exactly this in mind, eliminating smoke and getting better combustion. (Note that this was known in the mid 19th century, they knew how to burn smokeless!) The firebars of the stoker were in constant motion driven by cams on the front. They were timed so that individual bars were moved back in turn allowing burned clinker and ash at the back of the fire to fall into the ash pit. When all the bars had been drawn back the whole grate moved forward coinciding with the ram pushing another charge of green coal on the coking plates. Given sufficient load this meant that you could manage the speed of operation and feed to produce an even firebed thick enough to produce optimum combustion in which the coal was completely consumed just as it reached the end of the bars. It was a simple matter under these circumstances to regulate the damper opening. Once the fire was settled, you gradually cut the combustion air down unto the stack started to smoke and then increased the draught a little until you had a light haze at the chimney top. This basic principle of maintaining a white hot fire and regulating combustion air applies to oil fuel as well.
So why, with a good boiler and stoker (Although like any other engineer running a boiler I'd have liked an extra 30ft on the stack so I could play with the draught!) did we get into trouble? I'll tell you tomorrow.