Talk:LMS Class 7F 0-8-0

Untitled

These were a kind of locomotive right? So say so. m.e. 12:02, 4 November 2006 (UTC)

Right! I have added steam locomotive. 82.21.65.109 11:16, 25 March 2007 (UTC)

But somebody has just reverted it! 82.21.65.109 11:26, 25 March 2007 (UTC)

Why? 82.21.65.109 11:28, 25 March 2007 (UTC)

Restored steam locomotive. 82.21.65.109 13:21, 25 March 2007 (UTC)

Overview

Most of the overview section is hearsay. Could we have more specific references please? "E.S Cox, writing in a series of articles in Trains Illustrated c. 1957, suggests that they had a sufficiently modern and effective front end that, for steady slogging, some drivers preferred them to an LMS Stanier Class 8F". Didn't the Stanier Class 8F also have a modern and effective front end? If so, what was the reason for the drivers' preference? Biscuittin (talk) 11:11, 23 February 2012 (UTC)

Comparing the two, the 8F has a bigger grate and a bigger heating surface but the 7F has a bigger superheater. Possibly this made the 7F more efficient, so it could haul the same load with less shovelling of coal. However, this is speculation. Biscuittin (talk) 19:56, 23 February 2012 (UTC)

The 7F is a Fowler boiler design, out of Crewe running gear, with modern and improved front-end draughting. The 8F is regressing to Churchward's caution on superheater design. The 7F could make use of the additional superheat in a way that other locos of the period often couldn't. The 8F probably could have done too, but wasn't given enough superheat to really show it. When Stanier did break free of Swindon, some of his designs were over-superheated (i.e. too much superheater, leading to less superheat actually achieved). Andy Dingley (talk) 22:14, 22 November 2015 (UTC)

Bearings

The story that drawing office staff were responsible for the inadequate bearings sounds highly improbable to me. Surely the Chief Mechanical Engineer would specify the size of the bearings. He would be the person who got the blame if the engine did not perform well. Biscuittin (talk) 21:55, 22 November 2015 (UTC)

CME's don't do detail drafting. Largely they don't even design locos, they just give directions as to where new designs should be aiming. This wasn't a new design, it was just the LMS standarised flavour of the preceding LNWR 8-coupleds. Now in this (and the many other cases) he could be said to have overlooked the evident bearing problem and that had grown to become the sort of problem that should have reached his attention. There's some excuse for this as a design problem with the early locos, and the first locos of a class, but the problem went on for far too long and was never addressed. The 4Fs in particular could be expected to be given a relatively small bearing area at their outset but by the last of these, the wartime built ones, it was ridiculous. Whether the Garratts (or these 7Fs) should ever have had it from the start is another matter. Personally I think Fowler had some excuse for using it, being a Midland man and "it having worked well enough in the past" but Stanier had no such excuse (as a GWR man he did know how a better bearing could be set out). The late batch of the 4Fs should certainly have been redesigned. Andy Dingley (talk) 22:10, 22 November 2015 (UTC)

Fowler was CME at the time that the 7Fs were built (100 straight off the drawing board without even trying out a small number as prototypes), and so was ultimately responsible: but it has been written that Fowler "never designed a locomotive in his life". He delegated, and E.S. Cox, in Locomotive Panorama (vol. I, pp. 67-68) mentions that 'Jock' Henderson, the Leading Draughtsman at Derby "was in the ascendancy", being responsible for the "first class cylinders", valves and valve gear. Cox also wrote "Unfortunately this excellence was tragically combined with undersized bearings, the inevitable and insufficient axleboxes of the Midland Class 4 freight engine again being used." The 4F bearings were themselves components dating back to Deeley's 3F 0-6-0. --Redrose64 (talk) 23:38, 22 November 2015 (UTC)

The small bearings have also been attributed to James Anderson (mechanical engineer). I think the Midland Railway, generally, just had a resistance to change. Biscuittin (talk) 19:47, 23 November 2015 (UTC)