Tunnel Portal Gradient

1:27 max.

It was posted in a forum somewhere, and which I copied the text, but not where it came from, the actual XR gradients as built:

1:27 Pudding Mill Lane portal to around Eleanor Street
1:28 either side of Woolwich station
1:30 at other places incl. other portals

The reason this came up on the other forum is pre-Crossrail, the post 1990 rebuild gradient of 1:29 up from City to Blackfriars*** on Thameslink was used - the value of 1:29 that is - within all main line multiple unit procurement specification as the maximum on any currently open NR main line. Traction kit must be capable of restarting a stationary train+++ on that grade with 50% traction power isolated. In discussing that, someone commented it had possibly now been changed to 1:27 - I enquired why - and those XR gradients were given as the answer.


*** there is also a very short 1:29 to the immediate west of Farringdon on Thameslink ex-widened lines section - but emphasis on this one is very short

+++ and trains stopped between City and Farringdon on that grade is a routine occurenc;e I see it and been on them often enough; small wonder they specified it - especially as a southbound train has just done its AC > DC transition at BFR (or CTK in default) and 700s (like 345s) consist of two seperate section that are not interconnected traction power wise _ possible scenarios are that one half could fail to changeover so the other half has to be able to move the complete train. Somewhere I have the 345 spec but not on hand; I am sure it will go into this somewhere for the XR route.

It is annoying these days how difficult it is to find out basic basic data like a gradient profile of a newly constructed line.

In days gone by - that is in the days when railway magazines were not full of corporate media soundbytes from pre-processed scripts and advertisorial articles - a full proper technical article on the core civils and electricals as well as the trains would have appeared by now.

Digressing, the last piece of main line rolling stock delivered to BR that had a full traditional unbiased new product write up avoiding contractual confidential no publicity clauses was CLass 58 locos back in 1983. Nothing since then: 1984 was the beginning of BR sectorisation. Yes something always gets written somewhere, but always with as many gaps as gen given. I can't remember the last time any LU stock had a full technical write up in any commericial mag ? I don't mean retrospective looking backwards historical items compiled after years of life, I mean gen at introduction. 3-4 years back I wrote a major article on Thameslink 700s for Todays Railways; one of the things I tried to do there was mimic the type of thing that used to appear in Modern Railways under Geoffrey freeman Allen editorship. There were still holes in the result. 345s (and indeed S-stock) are big gaps in this respect in the general commercial public domain. Perhaps I ought go try make some money .........

A bit like Fifteen Floors...

What, for comparison, is the gradient on Central Line EB and WB to Stratford Station? I seem to remember they had to float Loughton Branch Junction signal box on a raft of concrete to make the EB grade acceptable....

I would have thought the gradient at Bow Road is one of the steepest. My father used to drive trains up it and said he never noticed any difference, or strain, on the motors.

I have some data on some of this.

Central going west after Stratford station is 1:31 down for ~150 m then 1:50 down for another ~500 m

The same diagram set has short 1:25 twixt Holborn and TCR and again Notting Hill Gate and Holland Park; and on the Northern 1:24 between Borough and E&C; all of these sections are less than 100 m long _ having said that, gradients of that order are significant even when short.

I have been consulting "Improving London's Transport" the Railway Gazette supplement of May 1946. There is a description of the Loughton Branch Junction signalbox consolidation (with intriguing photo) on p24. The gradient east of Stratford is, annoyingly, not stated, but approaching Stratford from Mile End is given from Carpenders Rd, as only 1 in 45. (p.21).
It would have been known that the Standard Stock, with which the line opened, had coped easily with the 1 in 20s of the CLR, but these were for acceleration/deceleration.

I can only comment as I posted just above the data I have shows that as 1:38/1:39 not 1:28.

Repeat I can't further comment which is correct, only relay the data I have from current source.

Back to the original question.

Methinks in time the gradient data will appear.

The ELRs (engineers line references) for Crossail / Eliz.line are east to west :

LTN1
XRS / XRE
XRC
MLN1

Source =

www.railwaycodes.org.uk

e.g.

www.railwaycodes.org.uk/elrs/_mileages/x/xrc.shtm

This site does not do gradients but if you want to search this way is the best to find an ELR that you need here :


This site :

www.railwaydata.co.uk

specifically here :

www.railwaydata.co.uk/linefiles/

to find gradients; there is a station search box however I have found sometimes this might not give you the answer you want if you don't input the precise search term and some of those terms are not intuitive, which is why going via the ELR code sometimes works better.

Unfortunately, so far, none of the XR codes are available, but predict they will be in time as the site is maintained.