Transition curves, Superelevation and Cant on the LNER

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Hatfield Shed
LNER V2 2-6-2 'Green Arrow'
Posts: 1192
Joined: Fri Dec 23, 2011 3:34 pm

Transition curves, Superelevation and Cant on the LNER

Post by Hatfield Shed »

Anyone here knowledgeable about LNER track standards in respect of curves on the fast routes? I literally know nothing, beyond the description of the A4 press demonstration run ahead of the Silver Jubilee service commencement; which demonstrated that transitions from tangent to curve were too abrupt and there was cant deficiency at the speed the A4 could deliver.
Mickey
GCR O4 2-8-0 'ROD'
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Re: Transition curves, Superelevation and Cant on the LNER

Post by Mickey »

I can't answer your technical questions directly Hatfield Shed regarding the LNER fast lines curves other than from reading about the GNR many years ago which subsequently became the LNER which states that the GNR main line from Kings Cross was world renowned for 'it's straight lines and long sweeping curves' as opposed to the LNWR main line from Euston.
Original start date of 2010 on the LNER forum and previously posted 4500+ posts.
65447
LNER A4 4-6-2 'Streak'
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Joined: Fri Oct 19, 2007 2:44 pm
Location: Overlooking the GEML

Re: Transition curves, Superelevation and Cant on the LNER

Post by 65447 »

It is likely that the LNER applied the same design criteria as other railway companies, which were no doubt described and tabulated in such as the Permanent Way Institute's handbooks.

The deficiencies to which you allude no doubt resulted from the prior use of a lower design track speed, appropriate at the time but inadequate for the newly possible higher speeds of certain traffic workings.

There are implications for employing longer transitions, both in the horizontal and vertical planes, for traffic that was unable or was not intended to travel at the design speed, linked to the degree of cant; have you felt uncomfortable sitting at a disturbingly odd angle in a stationary or slow moving train on a section of track superelevated for high speed movement? And of course a much greater acreage of permanent way was required to accommodate the longer switch rails in points.

The problem was of course repeated with the introduction of trains working at, in the case of the ECML and other principal lines, 125 miles/hour and subsequently 225 km/hour speeds.

It was an engineering challenge, given the thousands of route miles constructed to a particular standard, that the APT was intended to overcome by eliminating the need for extensive relaying and realignment.
Hatfield Shed
LNER V2 2-6-2 'Green Arrow'
Posts: 1192
Joined: Fri Dec 23, 2011 3:34 pm

Re: Transition curves, Superelevation and Cant on the LNER

Post by Hatfield Shed »

That's a good lead to the PWI, thanks.
65447 wrote: Wed Apr 21, 2021 4:00 pm ... have you felt uncomfortable sitting at a disturbingly odd angle in a stationary or slow moving train on a section of track superelevated for high speed movement?...
Worse yet than that, one of a small group of friends struggling off the train at Oxenholme for the branch to Windermere with a heavy rucksack in 1971. Quite apart from the 'uphill' movement required, and pushing the door against gravity, a Westerly half gale just added to the merriment.
silverfox
GER D14 4-4-0 'Claud Hamilton'
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Re: Transition curves, Superelevation and Cant on the LNER

Post by silverfox »

Ahh the APT. Took a ride on a run from Glasgow to Preston.IIRC ran in an advertised spot,early dep, and only one price. Sotired 1st and 2nd seating
First couple of curveswere 'funny'but after that a super ride.
Also anyone else remember the G*R gimmick when the HST came out 125mph for 125p ?
Travel on any HST service Did some milage when that was on.Took my mateto Barry Scrapyard. Was still a lot of stuff there

Now it is a mortgage to get anywhere at a resonable cost.
Merrymakers there was another great idea
NSE did a Reading to Folkstone through service inc boat fare to Boulogne back in the 80s

Reading,Wokingham Bracknell,Ascot, Staines, CJunctn then non stop to Folkstone
. Great days out
No chance now no locos or rolling stock!!! all bloody units

Sur Le Continent they still have 15 coach loco hauled stuff.Things dreams are made of

Rant over now back to LNER stuff
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