What is a 'Gedge Flat' as seen on certain railway couplings?

Can anyone please explain the purpose of a Gedge Flat as seen on ex LNER and LMS couplings? In some instances the flat appears to have been stamped with some sort of identification reference or was it perhaps some sort safety loading factor. I am sure someone out there will have the answer.

I always thought it was to allow the coupling link to fit through the slot in the coupling hook. Was this wrong?

Brian G

It appears on Doug Hewwon's drawing in ME 4702, p.562; below his photo of the full-size coupling on the NYMR locomotive. There it does look like giving a keyhole effect so a deliberate quarter-turn is needed to remove it from the hook.

A reader following the series and with a rather better "filing system" than mine might be able to confirm this from the drawing of the hook, if already published.

I have seen a gedge (though not knowing that's its name) on a lifting-tackle oval ring, used for connecting slings by shackles. Its purpose there is less obvious still, but is probably to ease fitting the ring to a hook with a spring mouse.

The numbers are there simply because it presents a convenient flat for them.

I just looked up the RCH drawing for wagon couplings and the link is 1 1/2" diameter with a 1" thick x 2" wide flat (I never knew it was called a "gedge" 2 1/4" long midway along one side. The matching coupling hook has a 1 3/4" hole broken out by a 1 1/16" slot. The top of the hook at this point is 2 1/8" wide, so the flat will pass easily through the slot, but there is no chance of accidental removal.

Brian G

Any chance of posting a copy of the RCH drawing?

Please excuse me if this is drivel … I know roughly two thirds of almost nothing about railway stuff.

Looking here: **LINK**

https://www.pnp-railways.co.uk/product/shackle-half-with-gedge-flat/

the purpose seems very obvious to me, because I bemoaned the lack of such a flat many years ago when we were having shackles proof-loaded.

The flat is to provide an area that can be number-stamped safely

After our shackles had been tested … some clown ground a flat on them so that he could stamp it.

MichaelG.

Interestingly, my copy of "Historic Locomotive Drawings in 4mm Scale" by F.J.Roche does not show the gedge on sheet DET/L1 for LMS locomotives. Strange because I have always had a good deal of respect for the accuracy of his work.

Roche is correct the drawing says details LMS Locos these did not have a gedge the couplings had a slot in them so the eye of a coupling shackle could pass through it. I hope this makes sence, gedges were normaly only used on freight stock.

Paul

I'd never heard of one before, but see P7 of this pdf, apparently named after a Mr Gedge
http://ambisengineering.co.uk/Couplings.pdf

I'm familiar with flats on Master Links on lifting gear to slot on knock through chain couplings, but never thought about it for locos. Various photos of those HERE as an example.
https://www.dawson-group.com/DS095-G80-Welded-Master-Link-With-Flat-for-Chain-Lifting-Slings-Wire-Rope-Lifting-Slings-pd473503.html

Bill

Edited By peak4 on 03/11/2022 23:41:55

I stand corrected, Bill

MichaelG.

Interesting to see the difference between Bing and Google for 'gedge flat' and just gedge and entires in various online dictionaries. Looks like someone who knows how needs to add an entry into Wikipedia.

Drawings are available online here Railway Clearing House Wagons, the coupling hook and chain is on drawing 1007.

Brian G