Tank engines on express workings

[Taunton]

The Sevenoaks derailment drew attention to the pitfalls of using tank engines on fast passenger trains. The high centre of gravity of the SECR 2-6-4 tank and the tendency for water in the side tanks to surge caused these engines to roll dangerously at speed, although in this case the condition of the track took some of the blame. The large 4-6-4 tanks of the LBSCR had to have their side tanks only partly filled and a well tank added to eliminate similar problems. Other railways which used tanks on express trains in pre-grouping days were the L&YR and the GWR, and both of those experienced derailments which brought the use of tank engines into question. In fact the GWR rebuilt some of its 0-4-4 tanks "back to front" as 4-4-0 tender engines, having started life as 0-4-2 tanks.

Notable to mention the GWR tanks, because the 14xx 0-4-2T, built quite late in the 1930s and derided by some for their older appearance, could put up a good turn of speed. Their classic was on the Chalford-Gloucester push-pull, whether hauling or propelling their coach, where they regularly would race (and beat) mainstream LMS, and well into BR days in the 1960s, expresses on the Bristol-Birmingham line, where the two ran parallel, adjacent and dead straight for about six miles into Gloucester. O S Nock, the longstanding train timer and writer, wrote he was once timing a northbound Jubilee-hauled express when they were actually overtaken by a 14xx propelling at over 70mph.

Apparently Hawksworth, their actual designer (he was chief draughtsman where Collett was CME) put a lot of standard main line loco components, such as full size valves, into them. Unlike Churchward, who came into the drawing office daily and would take up the pencil with anyone, Collett was more aloof, preferring to work in his office up at Paddington on admin and policy matters, leaving actual design to the team.

Water surging in side tanks is entirely a matter of design in not putting sufficient baffle plates in the tanks.

 

[Merle Haggard]

Notable to mention the GWR tanks, because the 14xx 0-4-2T, built quite late in the 1930s and derided by some for their older appearance, could put up a good turn of speed. Their classic was on the Chalford-Gloucester push-pull, whether hauling or propelling their coach, where they regularly would race (and beat) mainstream LMS, and well into BR days in the 1960s, expresses on the Bristol-Birmingham line, where the two ran parallel, adjacent and dead straight for about six miles into Gloucester. O S Nock, the longstanding train timer and writer, wrote he was once timing a northbound Jubilee-hauled express when they were actually overtaken by a 14xx propelling at over 70mph.

In defence of the LMS/LMR (if one is needed!); the Stroud line is at a considerable height above the Bristol one where the two join, so the GW had the advantage of gravity as their line dropped to the level of the LMS one.

On the subject of the SR Rivers; I was told that some of the SR Moguls we saw on shed bashes had started life as 2-6-4Ts and was even shown a photo of the 3-cylionder one in its original, impressive looking form. What I didn't realise was that the W class 2-6-4Ts, a familiar sight at Waterloo and Clapham J, actually had the side tanks, bunker (but sadly not the impressive rounded cab) which had been kept when the Rivers were rebuilt. In The Locomotive History of the S.E. & C. (D. L. Bradley) it's mentioned that a W was tried on Vic - Tunbridge W. W. services in 1948, as a possible stopgap before the (successful) introduction of LMS design 2-6-4Ts. It 'pitched and tossed its way down Oxted bank', and the signalman at Oxted was terrified by its approach. This suggest that, as you state, it was just poor tank internal design.

 

[30909]

In the early 1900 before WW1 the LBSR "Sunny South Express" was a regular working of a D Earl Marsh designed I3 4-4-2 tank. In 1909 I3 No.23 became a bit of a star turn. The Sunny South Express would exchange engines at Willesden with LNWR for their run through to Rugby. In November 1909 it was agreed by both companies to work the train through, turn and turn about. No.23 was to run through to Rugby having taken water at Willesden a trip of just over 77 miles, it never ran dry nor did it need recoaling its 3.5 ton bunker load taking it from Brighton, Rugby and return. On the LNWR the train weight was approx 250 tons and the average speed around 53 mph. This economy and performance was attributed to the very early use of a super heater in some of this class of loco, I think these runs qualify!

 

[70014IronDuke]

The Sevenoaks derailment drew attention to the pitfalls of using tank engines on fast passenger trains. The high centre of gravity of the SECR 2-6-4 tank and the tendency for water in the side tanks to surge caused these engines to roll dangerously at speed, although in this case the condition of the track took some of the blame. The large 4-6-4 tanks of the LBSCR had to have their side tanks only partly filled and a well tank added to eliminate similar problems. Other railways which used tanks on express trains in pre-grouping days were the L&YR and the GWR, and both of those experienced derailments which brought the use of tank engines into question. In fact the GWR rebuilt some of its 0-4-4 tanks "back to front" as 4-4-0 tender engines, having started life as 0-4-2 tanks.

But a River tank was tested on the GN and no riding problems were found. At least, I've read that.
the problem on the SE was the shingle ballast, which did not perform as well as granite ballast, surely?

 

[marsker]

I've seen photos from back in the 1950s and earlier, of V1/V3 tanks on Class A Newcastle - Middlesbrough workings, though by the time I was old enough to have a proper awareness of what was going on, these had gone over to DMUs.
These tanks were certainly used through into the 1960s on "The Norseman" and other services between Newcastle and Tyne Commissioners Quay. I think, though I'm not certain, that they also worked the summer Saturday Glasgow - Whitley Bay service between Newcastle and Whitley Bay, possibly also the northbound service which was routed via the Blyth & Tyne and reversed at Morpeth.