The GWR autotanks (14xx, panniers and prairies)

I would be very interested in other peoples views on these locos.

 

Odd question, what can you say? I love them, the usual suspects no doubt hate them

 

To me, they epitomise the Great Western branch line. Although I'm first and foremost a Southern man, I do have a particular soft spot for the 14xxs. I enjoyed riding behind (and in front of) 1450 when it visited the Bluebell , complete with auto trailer, a few years back.

 

The consensus appears to be that however good Swindon was at some things, Ergonomics was one of its weak points.

But yes, 14XX's Panniers & small prairies are good looking engines and competent

 

Yes, as an LMS fan, i like the 1400s too. I blame The Titfield Thunderbolt!

 

The small prairies weren't auto engines in GWR days. They were fitted for use in South Wales in the 1950s. Many of the surviving trailers date from that period too.

 

Not sure really why for example the GWR made 14xx and panniers, seems almost duplication of a small tank design. Was the 14xx designed for higher speeds ? What didn't they just choose whichever was better and make them ?

 

I suppose the answer includes better at what. AIUI 48s, 54s, 64s, 74s and 16s had a lot of components in common, (especially motion) and were as standard a group as the big outside cylinder classes. I imagine the 0-4-2s were probably easier on track and tyre wear than the 0-6-0s, maybe even a tad more economical on fuel with less friction esp on curves. They were also supposedly well capable of 60mph if it were needed. So that would seem to provide good reasons for having the 0-4-2Ts where the traffic demands were within their reach. Where it wasn't they had the 0-6-0Ts.

I would like to understand the maintenance regimes well enough to know where the big advantages in standardisation were. Clearly anything consumable that has to be regularly changed out in the sheds benefits from standardisation so the spares stock is as small as possible and there's no delays waiting for a spare to be manufactured at the factory and delivered. Similarly anything - like boilers - that requires time consuming work but can be maintained as a separate module benefits from being swappable. But with parts that would be rarely changed or repaired was there much to be gained? Got to balance the maintenance advantages with the suitability of the loco for the job.

You know I suspect that was part of where Riddles' team went wrong. At a guess they assumed that they'd have so many of each class that it wouldn't matter that there wasn't as much interchangeability between the classes as say Churchward had. In the end of course:

 

most of those locos were replacements for very similar older engines in any case. I imagine the 64xx were developed as a smaller wheel version of the 54xx as they were intended for South Wales in the main.

 

A 14xx & a 57xx are completely different animals - 57xx for plenty of grunt & lever reverse for shunting whilst the 14xx is a faster, economical, larger wheeled light load loco with screw reverse. 54xx/64xx/74xx have more similarities to the 14's where a bit more power was required on similar duties.

Tank engines of this size were built in large numbers over long periods with ongoing development. Their roots can be traced back to earlier designs together with some basic differences between Swindon design practice & that of Wolverhampton works.

 

not sure why you mentioned the 57xx

 

Why was there felt to be a need for auto fitted small prairies?

 

Purely a pragmatic decision...

A lot of the early auto-fitted locos (e.g. 517s, 1076 panniers) where reaching the end of their lives and were being withdrawn. And yet there where still auto-worked diagrams to cover.

So Swindon fitted auto gear to available locos still with plenty of life in them - even if they where a tad larger than the duties required. Once so fitted they were mainly to be found in the welsh valleys where the gradients made the extra grunt useful.

 

IIRC that arose from accelerated/improved services in the South Wales area in the 1950's just pre the DMU era. Perhaps these required extra power for gradients, rapid acceleration to keep time etc.

 

All the Collett auto fitted locomotives had screw reverse, 48s, 54s, 64s. 74s and 16s had lever reverse.

Think you'll find they were all gone some years before the Prairies were converted.

My guess is 1472 is right - it was accelerated services, particularly one imagines faster turnrounds. Thinking on that a bit more, would the small prairies, all 4575s IIRC, have had enough extra water capacity to be able to do more trips without stopping for water?

 

Your comment sent me to my books to check and you are right - the last 517 went in 1947 and the last 1076 in 1946. These were the last scattered survivors with most withdrawals significantly before that.

A quick delve into other references indicates that the 45xx fit with auto gear started in 1953 as a result of the introduction of "regular interval" timetabling in the Welsh valleys generating a significant increase in the number of turns requiring an auto fitted engine - according to the RCTS. The 45xx well known capacity for rapid acceleration made them ideal candidates. Until DMUs came along...

 

Our small prairie 5572 at Didcot, was one og those fiited with autogear in the 50's. However I am sure she spent some of her life in Devon

 

The Titfield Thunderbolt was what started my love for the 14xx's

 

I believe the auto coaches used in the Valleys included converted coaches, some at least non corridor. Photos would be good....

 

94xx & 15xx are lever reverse. But then so are 45xx albeit they are piston valve locos so easier to notch up without shutting off steam.