Gresley's engines were considered elegant, both aesthetically & mechanically. His invention of a 3-cylinder design with only 2 sets of Walschaerts valve gear, the Gresley conjugated valve gear, produced smooth running & power at lower cost than would have been achieved with a more conventional 3 sets of Walschaerts gear.
Gresley was born in Edinburgh during his mother's visit there to see a gyno, but was raised in Netherseal, Derbyshire, a member of a cadet branch of a family long seated at Gresley, Derbyshire. After attending school in Sussex & at Marlborough College, Gresley served his apprenticeship at the Crewe works of the London & North Western Railway, afterwards becoming a pupil under John Aspinall at Horwich of the Lancashire & Yorkshire Railway. After several minor appointments with the L&YR he was made Outdoor Assistant in the Carriage & Wagon Department in 1901; in 1902 he was appointed Assistant Works Manager at Newton Heath depot, & Works Manager the following year.
This rapid rise in his career was maintained, for he became Assistant Superintendent of the Carriage & Wagon Department of the L&YR in 1904. A year later, he moved to the Great Northern Railway as Carriage & Wagon Superintendent. He succeeded Henry A. Ivatt as CME of the GNR on 1 October 1911. At the 1923 Grouping, he was appointed CME of the newly formed LNER.
In 1936, Gresley was awarded an honorary DSc by Manchester Uni. & a knighthood by King Edward 8.
During the 1930s, Sir Nigel Gresley lived at Salisbury Hall, near St. Albans in Hertfordshire. Gresley developed an interest in breeding wild birds & ducks in the moat; intriguingly, among the species were Mallard ducks.
In 1936, Gresley designed the 1,500 V DC locomotives for the proposed electrification of the Woodhead Line between Manchester & Sheffield. WW2 forced the postponement of the project, which was completed in the early 1950s.
Gresley was awarded the CBE in 1920 & was knighted in the 1936 Birthday Honours.
Gresley died on 5 April 1941, after a short illness, & was buried in St Peter's Church, Netherseal, Derbyshire.
A memorial plaque to Gresley's achievements was unveiled at Edinburgh Waverley railway station in 2001. It was created by the Gresley Society & incorporates line drawings of his Flying Scotsman & Mallard locomotives.
A statue of Gresley was unveiled at King's Cross station on 5 Apr. 2016, the 75th anniversary of his death. Sculptor Hazel Reeves originally included a duck alongside Gresley in reference to his hobby of breeding water fowl & his bird-themed locomotive names such as Mallard, but this was removed from the final design when two of Gresley's grandsons complained it was "demeaning".
Sent me by Steve Sattler
I visited the Flying Scotsman in New York on it's tour in 1969. I've also seen the statue of Gresley, I think a Mallard would have been a nice addition but that sure wasn't my call. King's Cross has been renovated and is as nice as St. Pancras. There is evidence of bomb damage from the Blitz that you can see here and there.
daveklepperA statue of Gresley was unveiled at King's Cross station on 5 Apr. 2016, the 75th anniversary of his death. Sculptor Hazel Reeves originally included a duck alongside Gresley in reference to his hobby of breeding water fowl & his bird-themed locomotive names such as Mallard, but this was removed from the final design when two of Gresley's grandsons complained it was "demeaning".
(Photo by Alan Stanton)
If you had him holding the duck lovingly ... it might be hard to make any railroad connection as to why he was there. Having him hold a model of Mallard lovingly ... a little better but still odd. Sticking those things on the floor next to him just wouldn't work...
BTW, Mr. Klepper needs to tell Mr. Sattler that he has succumbed to propaganda. Mallard never reached 126mph; that was an artifact of the hydraulic dynamometer gear and acknowledged by Gresley as such; the correct number is 125, which itself was only reached for a comparatively short time. This may seem like a little thing, but you will note that among other things, the exaggeration eliminates the DR 05 class from 'holding the record'...
I might add that the ruined-big-end issue is largely immaterial; a corrected design that I think would have tolerated the record-run loads was quckly put in place for the remainder of the A4s' lives. Less easily solved are the issues of whip and multiplying clearances in the conjugating gear that overloaded the inside big end in the first place.
There's some that say this locomotive broke "The Ton" in 1904. It's in dispute and I imagine rail buffs across the U.K. would discuss it for hours over a pint at the pub.
https://en.wikipedia.org/wiki/GWR_3700_Class_3440_City_of_Truro
About 10 years ago I was on a trip pulled by the Truro at the Mid-Hants railway. It's been retired but damn, it was a fine looking machine.
Overmod I might add that the ruined-big-end issue is largely immaterial; a corrected design that I think would have tolerated the record-run loads was quckly put in place for the remainder of the A4s' lives. Less easily solved are the issues of whip and multiplying clearances in the conjugating gear that overloaded the inside big end in the first place.
How is a 3rd valve gear placed if one is not using the conjugating arrangement?
Chapelon's 242-A1 placed a second eccentric outside the wheels that was connected to the Walschaerts expansion link and combination lever inside the wheels? With the connection through a "rocking lever" style bell crank?
Was this the usual way to do this?
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
Paul MilenkovicHow is a 3rd valve gear placed if one is not using the conjugating arrangement?
Porta apparently had some discussion of ways to implement this on a 100mph engine in his long dissertation to the A1 Trust in the early Nineties -- I suspect peppered with words in CAPITAL LETTERS. The issue with hanging the 'third gear' off one side of the engine is that much of the cross-augment becomes more difficult to address, and compensating via a balanced eccentric crank and bobweight on the 'other side' of the affected driver pair just makes the overall augment larger. (In partial defense of the idea, if the hammer-blow eccentricity is reduced, the absolute effect of coordinated augment (both wheels 'hammering' together' as it were) can allow surprisingly high road speed, as in the last generation of English 2-10-0.)
Examples of a 'good' third-valve-gear setup are epitomized in some of the late UP Nines and the postwar Polish 4-8-2s; there are of course other examples. Of course there are benefits in driving all three valves from the rear, and in general the valve chest for the center cylinder (whether or not it is angled so its connecting rod 'clears' driver lateral-motion cannon boxes, a more serious constraint than what is possible with the usual cranked-leading-driver axle setup) will be tilted over to the side where the 'third gear' is located to minimize the bell-crank arrangement.
There have been some experiments in using different geometry for conjugation. One notable idea tried in Australia was to use rotating shafts rather than levers to get around the issues of lever deflection and progressive lost motion. The problem -- imho easily predictable -- was that in the original application the shafts had too much of the wrong kinds of torsional flex. My version of this would use fairly large-diameter 'pipe' for the shafting (and ratcheting-cage rolling element bearings) -- think of this as the extreme version of a hollow axle -- and probably intermediate large-diameter roller bearings rather than 'split' to control any bending deflection.
There were two quite different applications of "rotating shaft" conjugated valve gear in Australia.
The first was used on Victorian Railways 4-8-4 H 220, which is fortunately preserved, if not in working order. This was a German design dating from 1915 which predated the Holcroft design adopted by Gresley. In fact, Gresley's first three cylinder locomotive used a version of the German design, which was patented by Henschel One assumes the arrangements for using the Henschel design in Victoria were settled some time prior to 1941 when H 220 appeared. The cross shaft on this locomotive appeared to be around !0 inches in diameter which should meet the "hollow axle" description.
Some history and description of Holcroft's design as adopted by Gresley can be found at:
https://www.lner.info/article/tech/valvegear/gresley.php
This site has a very good listing of all LNER steam locomotives.
The other design used on the NSW D58 was a rack and pinion drive version of the Gresley gear.
However in this design the racks were the item that moved, driven by gear sectors on a rotating cross shaft. The cross shaft replaced the 2:1 lever, while the 1:1 lever was moved forward and back on a slide actuated by the gear on the cross shaft.
I'm not sure what was expected to be gained by this design. When first applied it was fitted to the locomotive frame but after the locomotive was first lifted, the mechanism locked solid. The gear was redesigned to sit on a platform bolted to the front of the cylinder block and it at least worked.
The main theoretical objection to the Gresley arrangement, which Holcroft warned Gresley about at the time they first discussed it, was that expansion of the valve stems upset the valve settings. The outside cylinder valves are fixed at the rear and expand foward while the centre valve is fixed at the front and expands to the rear. Since valves can only be set cold the changes required to compensate can only be estimated. In general, this resulted in more power being developed by the centre cylinder. Edward Thompson reduced the centre cylinder diameter of a number of Gresley A4s by one inch to comensate for this power imbalance, which appeared to get worse with increasing speed.
I don't know of any illustration of the D58 gear on line.
There is video of D58 class in action, on a very short steep section of line (1in 40, 2.5%)
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