Gresley W1 'hush hush' loco

[neildimmer]

The LNER W1 No. 10000 (also known as the Hush-Hush due to its secrecy) was an experimental steam locomotive fitted with a high pressure water-tube boiler. Nigel Gresley was impressed by the results of using high-pressure steam in marine applications and so in 1924 he approached Harold Yarrow of shipyard & boilermakers Yarrow & Company of Glasgow to design a suitable boiler for a railway locomotive, based on Yarrow's design.
The locomotive was completed at Darlington Works in 1929.
The locomotive had a corridor tender and ran non-stop London-Edinburgh services to time in 1930; nevertheless steaming was relatively poor during test runs, and in spite of a number of modifications initially to the exhaust, boiler performance never reached the standards of an equivalent firetube boiler. A problem never fully solved was air leakage into the casing.

Rebuilding

When it was deemed that no further progress could be made, the locomotive was taken to Doncaster Works in 1936 and rebuilt with a conventional boiler and three simple expansion cylinders on the normal Gresley layout. A modified A4 boiler was fitted which had 50 sq ft (4.6 m2) of grate area and 20 in (508 mm) diameter cylinders. The valves were considered undersized for the large cylinder diameter and this somewhat limited the speed capabilities of the engine. Its haulage capacity was nonetheless appreciated The rebuilt engine still retained its additional axle, resulting in a more spacious cab for the driver and fireman.
No. 10000 never carried a name, although it did carry small works plates on the smoke deflectors bearing the number 10000. In its early form, it was known unofficially as the Hush-Hush as a result of the initial secrecy surrounding the project, and also the Galloping Sausage as a result of its bulging boiler shape. Plans in 1929 to name the original engine British Enterprise were dropped, although nameplates had already been cast; a 1951 plan to name the rebuilt engine Pegasus did not come to fruition either. From 1948 under British Railways it was renumbered 60700.
On 1 September 1955, 60700 had just departed from Peterborough when the front bogie frame broke. The locomotive derailed at a speed of 20 miles per hour (32 km/h) at Westwood Junction. It was recovered and repaired

60700 was withdrawn on 1 June 1959 and was broken up for scrap at the Doncaster Works later that year. One of its tenders did survive into preservation. Tender No. 5484 is now attached to No. 4488 Union of South Africa

I have added a large collection of photos featuring this loco in both guises

Including this photo of
60700 with a bit of bother at Hitchin 15th July 1954
https://tinyurl.com/y3t9vxk8

10000 as built
https://tinyurl.com/y52sz7sc
10000 now rebuilt
https://tinyurl.com/yxpha6dt
and as
60700
https://tinyurl.com/y2wnbnw9

Neil

https://tinyurl.com/y3t9vxk8

[silverfox]

Just digressing, but still W1

There is a chap on a Modelling forum ( peter knows about it) who is building a hybrid of the W1. The workmanship is excellent, but it is the original shape above ( with a normal firetube boiler, i think the original watertube may well not get past the boiler inspectors of clubs!!) and the rebuilt chassis with 3 cyl. sort of not one thing nor the other
It may well be my way of thinking, but if i were doing a W1 i would do the compound chassis rather than the normal Gresley configuration

Still each to his own