Loco push-pull apparatus

[nberrington]

Greetings all
Does anyone know where I can find drawings of (and hopefully an idiots guide to...) the push pull apparatus as found on ex-LSWR M7’s?
I have several photos, but no detailed breakdown. There are all kinds of tanks, pipes and cylinders.....

[FCA]

I couldn't find any drawings for my pull/push fitted H class (Snooze 229) so worked from photos. Scouring the internet turns up dozens of possible sources. I used a variety of components including a modified Gibson Westinghouse pump, a few components from the SE Finecast kit and home brewed air tanks on top of the side tanks and between the front frames.

The result may not be 100% correct, but looks about right.

thumbnail_IMG_0023.jpg

Richard

[Noel]

I'll admit to not knowing how the SR system works, and various parts are different on H, M7 and O2, but what is common to all three are VB pipe, steam heat pipe, and three air pipes on each buffer beam, although placement varies, and the air pump on the smokebox to maintain pressure in the air reservoir(s); this has a steam connection from the boiler, an exhaust to the smokebox, and a small pipe to the reservoir(s), plus some means of automatic control to activate it when the pressure drops. The number and location of visible actuators varies between classes and perhaps individual locos within classes. I would not be surprised to find variations between locos in the exact shapes of individual pipe runs, as such details were often left to 'shop floor' discretion. The H class reservoir was underneath the front footplate like that of the M7, and, being a pressure vessel, would be a casting with the ends cast and fitted separately. I haven't found a clear view of the cylinder on an H, but the M7 cylinder and the two on an O2 clearly have the connecting pipes in the ends.

[Winander]

According to this site https://caledoniaworks.com/product/lswr-m7-class/

When in 1912 the LSWR introduced push-pull services on some branch lines many of the class were fitted with a cable and pulley system of operation. However the Southern Railway subsequently adopted the LBSCR compressed air control system and thirty six of the class were converted to this between 1930 and 1937. Because of the extra space need to fit the compressor these conversions were confined to long framed members of the class, and a further four rather late conversions appeared between 1960 and 1962 as a result of frames being exchanged during overhaul.

No idea if it is significant or relevant, but appears you can broaden your search to LBSCR sets.

[John Palmer]

Could see nothing relevant in the BR engineman's handbook, but then had an inspiration and found the attached in the Southern Railway's "Practical Hints for Footplate Men" (undated, but frontispiece is a Bulleid Pacific in Sunshine livery). Quite a good diagram of the apparatus, and the text may be of interest too.

[Daddyman]

Could see nothing relevant in the BR engineman's handbook, but then had an inspiration and found the attached in the Southern Railway's "Practical Hints for Footplate Men" (undated, but frontispiece is a Bulleid Pacific in Sunshine livery). Quite a good diagram of the apparatus, and the text may be of interest too.

I should have gone with my instinct and directed Neil to Western Thunder, where the exact same diagram appeared a few days ago. But I didn't know that the LBSC and the LSW didn't differ. Anyway, I now can't find the thread on WT! As for how to model it, is this any use?
https://www.westernthunder.co.uk/thread ... d-m7.7613/

[bécasse]

Here is a version of the same file re-orientated and page cropped:

SR Push Pull Note.pdf

[bécasse]

The "three" (strictly four) main Southern pre-grouping companies all used different pull-and-push systems, the LSWR and SECR using mechanical wire-based arrangements and the LBSCR using air. Sensibly, particularly as it started to use pull-and-push more and more, the Southern decided to standardise on the Brighton system which was the most flexible and reliable, and locos and vehicles equipped with the mechanical legacy systems were gradually converted to air.

The Southern described its pull-and-push trains as "Motor" or "Motor Train" in its WTT and such trains could comprise up to three vehicles either side of the loco, some U-vans were pull-and-push equipped and used between the loco and the coaching stock on services which had a heavy demand for the conveyance of prams and some "long-ten" ex-SECR thirds were also so equipped and used to strengthen the normal two-carriage pull and push set. The only case that I know of of the regular use of three car formations both sides of the loco, ie six cars in all, was on the emergency shuttle service between Faversham and Herne Bay which operated for several months after the line east of Herne Bay was completely washed away in the 1953 floods.

[ted.stephens]

Does anyone have any photos they can share on this thread showing the arrangement inside the cab for an M7?

[Daddyman]

Does anyone have any photos they can share on this thread showing the arrangement inside the cab for an M7?

Scroll down the WT thread I linked to. (You may have to join WT to be able to see photos.)

[Philip Hall]

Also the Southern called them ‘pull-push’ as opposed to ‘push-pull’!

Philip

[Hardwicke]

The Southern described its pull-and-push trains as "Motor" or "Motor Train" in its WTT ...some "long-ten" ex-SECR thirds were also so equipped and used to strengthen the normal two-carriage pull and push set.

After the Swanage 10 compartment ex SECR was damaged and scrapped a BR(S) non corridor suburban was used.