Shear legs

[Blackstoat]

Hi

 

I spotted the shear legs in the attached picture at Doncaster last week.

 

Unfortunately the kids were playing up at the time and I didn't have time to talk to the end exhibitors.

 

Does anyone know if the shear legs are available as a kit in OO?

 

Thanks

 

Andy

[teaky]

It's a Ratio kit Andy.

[Daddyman]

Surely no loco was ever lifted that high by one end only, was it? And supported on its injectors/drag beam?! 

[Blackstoat]

It's a Ratio kit Andy.

Thanks mate

[The Johnster]

Thanks mate

 

Described as a hoist on their website.  Not sure a sheerlegs (the spelling I know it as, which of course may not be correct) is exactly the same thing.  Crane experts to the forum. please...

[DCB]

Don't think the GWR went in for that sort of thing, it looks far too modern.  It should really have a Midland 4F dangling from it not a GWR 4 cylinder loco. A hot box was a big issue on the GW bearings had to be sent to and from Swindon, the LMS could turn round a 4F in a couple of hours, they had plenty of practice.

[teaky]

Described as a hoist on their website.  Not sure a sheerlegs (the spelling I know it as, which of course may not be correct) is exactly the same thing.  Crane experts to the forum. please...

I'm not a crane expert but I'd have spelt it "shearlegs".  I agree that it isn't the same thing though.  I think of shearlegs as simple three-legged cranes or hoists.

[teaky]

Surely no loco was ever lifted that high by one end only, was it? And supported on its injectors/drag beam?! 

I agree.  I've never seen a picture of anything so drastic.  I thought they only lifted locos enough to be able to roll the bogie and/or driving wheels out, i.e. take the weight + several inches.

 

Hopefully there will be someone on here who has actually done this either on the real railway or on a preserved line.

[jamie92208]

They were very common on some lines. The Midland had shear legs at most sheds, other companies had wheel drops. As mentioned above locos were usually only lifted enough the roll the offending wheelset out. There is still a set of intact Midland shearlegs inside the roundhouse at Barrow Hill. The design was always essentially a tripod though one leg might actually be made of two beams for extra strength. I'm having to scratchbuild a set in 7mm. This is a rather poor camera phone picture of the state of play about a year ago. The key to it is the top plate which ahs sockets that hold the tops of the four timbers at different angles.

This is what it will look like placed at the back of the shed.

 

Jamie

[Gordon A]

The loco is lifted too high.

It would only be lifted high enough say for the front driver bearing to clear the chassis and for the wheel rims to clear the underside of the outside cylinders by a few inches.

 

Gordon A

[Daddyman]

I agree.  I've never seen a picture of anything so drastic.  I thought they only lifted locos enough to be able to roll the bogie and/or driving wheels out, i.e. take the weight + several inches.

 

Hopefully there will be someone on here who has actually done this either on the real railway or on a preserved line.

Donald Peddie's Scottish Railways: Two Decades of Transition on page 52 shows a couple locos that have been lifted by shearlegs, and it is precisely this - to allow the loco's driving wheels or bogies out, and an accommodation bogie to be slid underneath. 

Edited February 20, 2017 by Daddyman

[The Johnster]

I'm not a crane expert but I'd have spelt it "shearlegs".  I agree that it isn't the same thing though.  I think of shearlegs as simple three-legged cranes or hoists.

 

Shearlegs it is/they are, then; I stand corrected!

[stevejjjexcov]

This is described by ratio as a lifting hoist. I do agree that the loco is lifted far to high and with two wheelsets missing? I would guess that a job of that magnitude would have been done at Swindon with the loco parallel lifted. Just my take on it

 

Steve

[34theletterbetweenB&D]

Surely no loco was ever lifted that high by one end only, was it? And supported on its injectors/drag beam?! 

 

One piece at a time. UK practise in frame design was that the entire locomotive could be lifted by the lifting holes in the frame ends; and at the time steam locos were designed the factor of safety was six for structural steelwork. As such there would be no structural problem with supporting the cab end on the drag box, provided any intervening tackle had been removed. But it wasn't done that way in photographs I have seen of such operations, the rear wheelset would be on the rails and supporting the back end of the loco. I believe the modelled scene to be a fiction. As the lift commences, the loco must roll forward and if borne on its rear wheels will do so. On the packing it would be static, until the resultant force overcame the friction and the whole loco moved rather abruptly forward, falling off the packing and 'we are in a mess'.

 

Second the angle, from the height it has been raised at the front end. I can immediately cite a couple of good photos in 'Top Shed' by Peter Townend, showing a Stirling single and N2 tank loco both at much the same angle, in order to release driving wheels, p27, 32.

[ejstubbs]

I'm not a crane expert but I'd have spelt it "shearlegs".  I agree that it isn't the same thing though.  I think of shearlegs as simple three-legged cranes or hoists.

 

OED says it's "sheerlegs" whereas  Wikipedia allows all sorts of variations including yours.

 

Regardless of the spelling, the characteristic attributes of a sheerlegs seem to be a rigid A frame with the 'feet' on the ground and the joint at the top guyed by one or more ropes, cables or poles.  Under load, the A frame is in compression and the guying component(s) are in tension, hence they don't need to be rigid.

 

The crane pictured in the OP definitely isn't a sheerlegs.

Edited February 20, 2017 by ejstubbs

[Mike Oliver]

The MPD at Grosmont on the NYMR has one of these lifting devices recovered from a BR loco shed. I have assisted lifting  steam locos to remove coupled wheelsets for attention to axleboxes. If the the driving (Middle) set is to be removed the loco has to be raised high enough for the middle set to pass under the front set and any truck or bogie. Essentially the OP illustration is a valid lift with the dragbox on packing.

[teaky]

 

OED says it's "sheerlegs" whereas  Wikipedia allows all sorts of variations including yours.

 

Regardless of the spelling, the characteristic attributes of a sheerlegs seem to be a rigid A frame with the 'feet' on the ground and the joint at the top guyed by one or more ropes, cables or poles.  Under load, the A frame is in compression and the guying component(s) are in tension, hence they don't need to be rigid.

 

The crane pictured in the OP definitely isn't a sheerlegs.

 

I'll go with the OED over Wikipedia.  I stand corrected.

 

Interestingly, there are numerous references to both spellings on the web but if you want to hire some it is best to spell it incorrectly. 

[jamie92208]

I believe that the origin was for use with ships for stepping the masts. The advantage was that they could be made out of spare spars that most ships carried.

 

Jamie

[Steamport Southport]

Don't think the GWR went in for that sort of thing, it looks far too modern.  It should really have a Midland 4F dangling from it not a GWR 4 cylinder loco. A hot box was a big issue on the GW bearings had to be sent to and from Swindon, the LMS could turn round a 4F in a couple of hours, they had plenty of practice.

 

Most of the larger GWR sheds had a repair shop with locomotive lifting equipment. There was no need to go to Swindon for anything other than major repairs and overhauls.

 

Old Oak Common's lifting shop had 12 roads.

 

http://www.davidheyscollection.com/userimages/00-0-a-map-OOC-b.jpg

 

 

Jason

[Steamport Southport]

The MPD at Grosmont on the NYMR has one of these lifting devices recovered from a BR loco shed. I have assisted lifting  steam locos to remove coupled wheelsets for attention to axleboxes. If the the driving (Middle) set is to be removed the loco has to be raised high enough for the middle set to pass under the front set and any truck or bogie. Essentially the OP illustration is a valid lift with the dragbox on packing.

 

 

I can't remember where they got them from, but the details are somewhere in the North Eastern Revival book. Definitely from one of the North Eastern sheds though.

 

 

EDIT:

 

Tweedmouth apparently. http://www.nelpg.org.uk/index.php?option=com_simplelists&view=simplelist&category_id=19&Itemid=37&limitstart=270

 

 

Jason

Edited February 20, 2017 by Steamport Southport

[The Johnster]

I'll go with the OED over Wikipedia.  I stand corrected.

 

Interestingly, there are numerous references to both spellings on the web but if you want to hire some it is best to spell it incorrectly. 

 

I'm going back to sheerlegs as well; no way I'm arguing with the OED.  I stand recorrected.  I was about to say deconnected, as I've reverted to my original way of spelling, but you can't stand deconnected as you'd fall over, which explains some of my antics on the way back from the pub...

[The Johnster]

I believe that the origin was for use with ships for stepping the masts. The advantage was that they could be made out of spare spars that most ships carried.

 

Jamie

That makes sense.  Old sea yarns featuring the likes of Cook, Bligh, etc, are full of drop of the hat instances of taking whole sailing ships to pieces, usually tipping them over in the process, and putting them back together with bits of some local forest purloined from the natives after scaring the $*@t out of them with a musket, then sailing them half way round the world to get home.

[The Johnster]

That makes sense.  Old sea yarns featuring the likes of Cook, Bligh, etc, are full of drop of the hat instances of taking whole sailing ships to pieces, usually tipping them over in the process, and putting them back together with bits of some local forest purloined from the natives after scaring the $*@t out of them with a musket, then sailing them half way round the world to get home.

 

There are instances of entire ships being built out of bits of the one you wrecked supplemented by local materials in this way.  Assuming your crew was more or less intact, and Cook's mostly were as he knew how to deal with scurvy, as did Bligh who learned from him, you had a labour force, a shipwright, a carpenter, and a whole load of guys who knew their way around ropes, blocks, tackle, and rigging.  The first thing you saved when you ran on to the reef was the sextant and a compass, followed very closely by the tools.

[jamie92208]

There are instances of entire ships being built out of bits of the one you wrecked supplemented by local materials in this way.  Assuming your crew was more or less intact, and Cook's mostly were as he knew how to deal with scurvy, as did Bligh who learned from him, you had a labour force, a shipwright, a carpenter, and a whole load of guys who knew their way around ropes, blocks, tackle, and rigging.  The first thing you saved when you ran on to the reef was the sextant and a compass, followed very closely by the tools.

There's a very good description as to how this was done in one of the Hornblower novels after his fight with the Natividad, including rigging a sheerlegs on a cliff top to lower a new mast into the ship. I can't remember which book it' in.

 

Jamie

[tomparryharry]

Working with a sheerlegs is quite involved, but straightforward. Firstly, select which end of the locomotive you are working on. For instance, lets say a 4-wheel bogie on a 4-6-0 locomotive. Position under where you intend to lift. Next, go to the opposite end, (cab end),and slightly lift, and pack up the locomotive frames. This provides enough height to get at what you need. By now, the axlebox keeps will be taken off, and the coupling & connecting rods as well.  Lifting the locomotive uses the rear packing as a bearing pivot, and allows enough bearing weight to allow the withdrawal of the bogie. as it lifts, the main driving wheels move through an arc. We would sometimes keep the driving wheels reconnected, depending on the wheelbase of the coupled wheels.

 

Cheers,

 

Ian.