Posts Tagged steam trains

From Steam to Ka, an essay on efficiency

Guest writer Gordon Pye looks at part of the efficiency of transport

Back in the 1870s Francis William Webb was an excellent steam locomotive engineer, having been trained by and followed in the footsteps of John Ramsbottom, the man who invented the piston ring. He introduced some really good designs like the express 2-4-0 Precedent ( Jumbo ) class, of which ” Hardwicke ” survives in the NRM today. He also introduce a cheap goods locomotive with patent cast iron wheels ( 17 inch coal engine four foot five inch wheels ), with an 0-6-2 tank engine version, for mixed traffic his ” Cauliflower ” 18 inch cylinders and five foot two wheels. All the ” goods ” designs lasted until after the second world war, Hardwicke was preserved due to it achieving 67 Mph average between Crewe and Carlisle in the great race to the North. A coal tank also survives in preservation.


However, in the 1880s Webb got it into his head that if you could use the steam twice in a ” Compound ” you could theoretically save coal, so he produced the ” Experiment ” class. It had two relatively small outside high pressure cylinders with a massive single low pressure cylinder between the frames. They were not really a success as they would not run at speed due to the exhaust from the high pressure cylinder being restricted when the synchronized valve gear was notched up. They were technically a 2-4-0, but the driving wheels were not coupled, Webb affected to discern that this allowed for free running but examination of the design reveals that there was not space for coupling rods to pass the Joy valve gear on the outside cylinder which drove the rear axle. ( low pressure drove the front driving wheels ).


The next design the 2-2-2 ” Teutonic ” had a far larger boiler, and the inside valve gear was a slip eccentric so that the low pressure cylinder was always in full gear allowing a freer exhaust. They were considered a success but one could only manage 64 Mph from Euston to Crewe in the race to the north. There were also potential problems setting off after an engine had backed onto the train, the slip eccentric was in reverse so in theory when one set of driving wheels could slip forward with the other slipping backward.


By this time the operating department were beginning to question the economy of the new compounds, so Webb organized a test where one 2 cylinder simple 0-8-0 large goods engine was run alongside another boiler identical 3 cylinder compound 0-8-0 up from Crewe towards Stafford. One man decided just how much coal was shoveled into each firebox so the test was obviously rigged to favor the compound and not scientific at all. It was claimed that the compound saved 5% on coal, perhaps insufficient reward for complicating anything.


The next step was the 2-2-2-2 Greater Britain class, which having trailing wheels slipped very easily, they also had a pointless intermediate combustion chamber in the long boiler. Webb painted one white and sent it for exhibition in the USA, I believe it actually pulled trains over there but suspect that the Yanks were less than impressed. Webb also built 10 John Hick class 2-2-2-2’s with smaller wheels for north of Crewe which were also totally useless.


By the late 1890s the operating department were getting desperate for a locomotive capable of handling the increasingly heavy traffic. They frequently had to resort to double heading but there were just about enough ” Jumbo’s ” about. Webb’s answer was a four cylinder compound 4-4-0, yet despite earlier experience the high and low pressure valve gear was synchronized. The result was totally useless but it was not until 1903 that the staff plucked up enough courage to compel Webb to resign, then after Moon ( Webb’s best mate ) the general manager had also gone. Webb also produced a four cylinder mixed traffic 4-6-0, of which it was said reached its low maximum speed by the time the train had exited the platform. Just for a second getting back to the recycling aspect it was said that said 4-6-0’s used the driving wheels from withdrawn 1860’s Ramsbottom DX 0-6-0’s.


Whale the new CME rushed out a 4-4-0 the ” Precursor ” class based on the ” Cauliflower ” which managed to do the job, a 4-6-0 with slightly smaller wheels for north of Crewe was also introduced. Crew works had to work flat out to replace all the Webb follies but by 1910 all the new Whale designs were rendered obsolete with the advent of superheating.


It would appear that especially automotive engineering is in a similar position to Webb in the 1890s. My 2006 1000cc Kia is no better in fuel consumption or performance than my ” tweaked ” 1989 1000cc Metro, admittedly running on leaded petrol. Perhaps the greatest unnecessary modern polluter is air conditioning, out in Aussie in 1987-88 it was said that you needed a 1600 Toyota Corolla with air conditioning to get the same performance as a 1300 without it.


Don’t have AC on my Kia, no point in this country and all that complete bullshit they put out about driving with the window down causing a significant increase in fuel consumption doesn’t stand scrutiny. The whole vehicle aerodynamics quasi-religion is complete bollocks, in the late 1970s we were told to ignore it as negligible in any motion calculation.


A 1980s OU programme I watched several times outlined that all you need to do for aerodynamic stability is to round the corners off on a square van. My practical experience tends to bear this out, my Seddon Atki 400 with 265L RR Eagle and 13 foot 7 inch tautliner was a good education. It seemed to take you ages to accelerate upwards from 50, then at about 57 it was just like falling through an invisible wall and you were soon doing close to 70. Just like the OU programme said, a vehicle will build up its own streamlining as speed increases.


The above statement would appear to prove my and others practical experience that when the 56 Mph EU speed limiters were introduced for trucks fuel consumption actually went up in many cases. Fuel consumption of 38 tonne cement tankers running from Clitheroe to Coatbridge ( return empty ) went up from 9 Mpg to only 7 Mpg. Of course other factors than air resistance come into play like the now inability to store momentum running at hills, but apart from the Lune gorge at Lancaster little opportunity for this exists on the road north loaded.


In truth today’s high tech HGV’s are no more efficient than those of the 1980s, cost a fortune to manufacture and maintain and probably have a higher total carbon footprint per mile run overall. It must be time to get back to basic ” cheap ” vehicles using proven technology. Likewise trains, even a 1958 2000 hp English Electric Class 40 would pull an express eight coach train at 1 Mpg, no modern DMU can match that and the result is that passengers are crammed into 3 cars like sardines.


Of course if the politicians ( particularly the Tories in the 1950s ) had taken the advice of the engineers all our ” main ” railways would all be electrified by now. R.A. Riddles first CME of British Railways resigned in 1951 after warning the politicians that if they went down the diesel route they would never be able to afford mass electrification. Its just a pity we went down the 25 Kv AC route ( to save money for fewer substations and on lighter wire ), 1500V Dc could have offered benefits like simple regenerative braking.


It would appear that we are in a similar position to what Webb was in 1900, perhaps time to break open the eco-fascist driven political quasi-religion and reveal it for what it actually is. Some commentators point to the probability that Webb was suffering from some type of mental illness in his later years. Webb was 70 when forced to resign and only lived three years in retirement at Bournemouth until he died in 1906.


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