Sir Nigel Gresley - The L.N.E.R.’s First C.M.E.

I think it is certainly not a good comparison. The German train is effectively a prototype and isn't doing anywhere near the service levels of the LNER trains.

 

It took fare paying passengers from june 36 to august 39.
206 seatsplus 23 for refreshments.
The waggons were wider and longer than UK ones I think
The germans found multiple diesel railcars faster and more usefull.

 

Been having a look at the LNER General Arrangement drawings for A3, A4, V2 and V1/V3 locos in my possession. All had roller bearings for the main pivots of the 2 :1 and the equal levers. The A3 and A4 had what I believe were needle type roller bearings in all the other connecting links. However, for the V2s (surprisingly) and the V1/V3 classes, for the connecting links it would appear that plain bronze bushes were used instead. It is presumably to these latter items and pins that E. S. Cox refers to having a clearance of 0.004" and an accumulated 'slop' of some 0.044" for the 11 joints even when new. In general engineering practice for a 'running fit' (i.e. as shaft revolving in an outer bearing) the clearance between the two would be 0.001" per one inch of diameter. Bearing in mind that the pins were/are 1 - 1/2" diameter, E. S. Cox's 0.004" clearance would appear to be on the somewhat excessive side when 0.0015" would be nearer the mark elsewhere. When needle roller bearings were applied to the A3s and A4s I would venture to suggest that clearances were virtually nil even compared with the 0.001 per inch of the plain bearings. It is quite possible that under wartime conditions the needle roller bearings were replaced by plain bronze bushes, whether this was also applied to the main 2 : 1 and equal lever pivots as well, I do not know.

 

Not at all. I am not claiming that Gresley was wrong to use three cylinders (with, of course, the conjugated gear) so extensively. I am questioning whether he was right or whether he overdid it.

A better overall package in what way?

 

More power available within the loading gauge, enabling higher loading/tare weights for trains. This would also lead to comparable or slightly better fuel consumption than the equivalent two cylinder. Certainly of benefit on the 2-8-0, 2-6-0 and 2-6-2T classes. We have some interesting data that suggests the latter classes were very competitive with contemporary two cylinder classes.

 

The Germans tested two versus three cylindered BR 03 in 1938 and found 6% higher indicated steam consumption for the three cylinder thing.
Cox (steamindex somewhere) stated that three- cylindered 2-6-4 used 56 lbs of coal per mile and the two-cylindered 52.

 

That's only true on lighter trains. When the three cylinder machines are used up to their maximum tare load (normally in excess of the equivalent two cylinder), their coal and water consumption becomes comparable. We are fortunate to have comparative figures for the L.N.E.R. fleet in terms of their coal/water consumption available in most of the RCTS books in that respect, and the trend is pretty clear in terms of where wastage occurs (normally putting three cylinder locos on shorter, lighter trains than required).

 

The Deutsche Reichsbahn compared 2 and 3 cylindered locos some 10 years earlier with classes BR 43 (2-cyl) and BR 44 (3-cyl) for comparison purposes. As the BR 43 only amounted to 35 locos, and up to 1945 some 2000 of the BR 44 were built, so in this case they obviously thought that having 3 cylinders was the better proposition.

 

The two cylinder 43 type had 720mm pistons and they costed more in maintenance than the threecylindered plus their higher coalconsumption.
Most of german freigth were fitted and the 43 were allowed to run 70 kmh forward and 50 backward.
The 44 was allowed 80 and 50.
The main excuse for threecylindered steam was speed

 

The BR 44 was chosen over the 43 because it had much better force distribution over 3 cylinders with less strain on the frames, and allowed smoother running at higher speeds.

The 44 and 43 were an entirely different size compared to most LNER goods locomotives though, and the tractive efforts these locomotives produced was at the point where cylinder numbers and sizes becomes quite relevant when discussing forces on the frames, especially when restrictive axle loads have to be taken into consideration. Their spiritual predecessors, the Preußische G12 had three cylinders for similar reasons as well, and so more power could be distributed over the lower axle loads they were built to.

 

Yes, Holcroft's patent and Gresley's were significantly different, and it's certainly possible that Holcroft's patent had minimal or no influence on Gresley's design. However that's not what Holcroft claims in his writing. His claim is that in a correspondence in "The Engineer" on the design of the first Gresley 2-8-0 and a paper to ImechE, also reprinted in "The Engineer", he outlined how the complexities of the valve gear design for that locomotive, which apparently had been criticised, could be significantly reduced. Have you been able to review that correspondence and paper? It would seem to be important primary evidence.

 

Yes, I did review it. I also think Gresley ignored Holcroft's recommendations. Hence my views.

 

Germany built the world's largest number of 3-cylinder locos, with the 3-cylinder 2-10-0s of Prussian Class G12 (BR58) and BR44 being by far the most numerous.

Germany did not follow the 3-cylinder path as consistently as did both Vincent Raven and Nigel Gresley in Britain. After a false start in 1902 with the Prussian T6 2-6-2T, the Prussian and Saxon Railways introduced several 3-cylinder classes in the 1915-20 period, some with the Henshcel conjugated valve gear. But in the 1920s, the new Reichsbahn Design Office under Richard Wagner generally favoured 2-cylinder options. In the 1930s, 3-cylinders came to be favoured again for the largest types, with huge numbers built of BR44 2-10-0 but only modest numbers of the 01.10 and 03.10 3-cylinder Pacifics. The LNER had a greater range of 3-cylinder types than the Germans, but did not multiply the Gresley P1 2-8-2, which was Britain's closest equivalent to the German BR44.

 

In fact the Germans ordered large numbers of three-cylinder pacifics of both 03.10 and 01.10 classes, though nothing like as many as the 2-10-0s. However, most of the pacific orders were cancelled because of the war and hence the gaps in the number series of those that were actually built.

 

I've been asked to share the above by a member of the RCTS - so please consider this as a heads up that I am giving what is likely to be my final lecture on Gresley ahead of publishing the book. All welcome!

The R.C.T.S. have been a great friend to me, with support for the Thompson book and research and now also the Gresley book by way of making available for publication many of the drawings they have collated over the years. I am very grateful to them for their support.

 

The story of the Einheitsdampflokomotiven is quite interesting on its own as there were many modifications and alterations made to the numbers of types of classes produced.

Originally they were all supposed to be built to 20t (with some exception designs for branch lines), but upgrading tracks to higher axle loads took much longer than expected, which is why the 03 light pacific, built to 18t was introduced and older designs like the Bayerische S3/6 continued production into the late 20e. If everything went to the original plan, then there would have been a lot more 01s and no 03s at all. Numbers of Einheits built were pretty miserable overall until WW2.

The 01.10 and 03.10 were designed to rectify rough riding at higher speeds and a lack of power, but they never got built in intended numbers. I’m not sure if using three cylinder designs was necessary for those needs though, since the 01 and 03 had huge potential and could have been improved significantly (as did happen after the war, particularly in the east).

 

The three cylindered pacifics were found nessecary and used for speed over 130kmh pre WW2..
This was neither possible or allowed on DDR tracks postWW2

 

I suppose I confused some by referring to the Eastern improvements to the pacifics, which didn't help their speed, but I was talking more about the fact that the two-cylindered 01s and 03s could definitely have been modified for better fast running, using a lot of the balancing improvements devised by the US. If they got the right treatments, these locomotives could have easily reached over 160 kph.

 

“If they got the right treatments”

But they didn’t. We have to deal in primary evidence. Supposition doesn’t get us closer to the truth as much as evidence does.

 

This is more my brainstorming than anything. I'm not really trying to prove a point.