Front couplings

When a loco is running chimney first on a train, the unused front coupling can be left dangling, parked on its own drawhook, or parked on a separate small hook which seems to exist purely for that purpose on GWR locos. The choice seems to be pretty consistent for any given class of loco. Is there any reason besides tradition (and whether the small hook exists) for which choice applies to which locos? How did the respective practices arise in the first place?

 

AFAIK on GWR loco's the coupling was held on a small hook to stop it battering the ATC equipment

 

Some had their ATC shoe at the rear of the loco.
https://flic.kr/p/mhjhWZ

 

When AWS - as opposed to ATC - was fitted so too was a plate, known as the bash plate, below the drawhook to prevent the shackle hitting the pick-up magnet. The plate curled up at the bottom and there was a slot in the curl into which the shackle could fit to prevent it swinging. The alternative way to prevent it swinging was to drop it over the hook, which was also commonly done.

 

We are always taught (and in fact have a specific rule in our rulebook to that effect) never to leave a screw coupling dangling - it must always be secured. We also never hang the loose end back over the draw hook, though I've seen that done elsewhere. Generally there is a small hook on the side of the buffer beam to hook the coupling shackle onto, or else (where the coupling can't swing sideways, as on some designs), a hook immediately behind the draw hook inside the buffer beam. If neither is available, our practice is to slot the tommy bar through the last link so as to raise it above ground level.

Tom

 

Irrelevant as to where the ATC shoe was - a dangling coupling will hit the ramp regardless.

 

It's good practice to not leave a coupling hook dangling. A swinging coupling will wear faster than one that is not free to swing. Back in my mining days the safety chains on mineshaft cages, which were slack, always wore much more quickly than those that actually supported the cage, which were tight. Putting the shackle on the drawhook can be a nuisance as it has to be moved before you can couple up although the rules said that you should always use that loco coupling unless coupling up to a loose coupled wagon, in which case you should use that coupling.

 

Is this becuase a loose screw-coupling can push itself off? Is there any reason why the first wagon couldn't be tighly-coupled to the engine using the screw?

 

If it's an unfitted train with three-link couplings between the wagons, you have a bit of slack between all of them. You want to keep that same slack throughout the train and not have the leading wagon hard against the loco. And you never use a screw shackle 'slack' as it can, as you say, come off the drawhook if the train closes up.

 

Thanks. Loose-coupled trains are a really bizarre thing when you think about it.

 

One reason. Screw couplings don’t like shock loads, either, as it can strip the thread.

 

A lot of people don’t believe a loose screw coupling can become uncoupled until they’ve witness it happen., which I’ve done twice.

 

And yet elsewhere: https://www.national-preservation.com/attachments/original-photos_002-jpg.87860/
That is just the first example I managed to find on here, with no implied cricitism of anyone. I am sure I have seen other similar pictures, hence my original question.

 

I've had a look through the 8F Society's Archive to find examples. These are all from that Archive, a couple from our own Neil Dimmer, and one from Ben Brooksbank. In several I found the shackle was swinging free, although later against the bash plate. Most show the tommy bar pushed through the lower shackle, and so far only one with the shackle on the drawhook. The one of 8033 includes some young idiot in a white jacket, otherwise known as me! But it shows the shackle in the slot of the bash plate.

 

How often were 8F's used on passenger trains?

I assume the acceleration could be interesting

 

More than you might think. They weren't uncommon on Saturday excursions and were also diagrammed to some local passenger trains: Manchester London Road - Buxton; Swansea - Salop over the Central Wales line; and over the S&DJR in its later years. All hilly routes. They were excellent going up the hills but struggled a bit going down the other side at speed. Their main problem was a lack of steam heat in winter (yes, three of them were CWA fitted and the sheds hung on to them like glue!).

 

Weren’t the three fitted with CWA to haul the royal train over the central Wales line? Two for the train and one as standby.

 

Correct! It's covered in H.C.H. Burgess's 'Working with LMS Steam':

On October 26th 1952, Her Majesty and Prince Philip travelled by Royal Train, via Shrewsbury and Craven Arms, to Llandrindod Wells, from whence they proceeded by road to inaugurate a new reservoir at Claerwen, a few miles west of Rhayader. (A plaque set in the platform now commemorates the spot where the Queen first set foot on Welsh soil after her accession to the throne.)

From Shrewsbury a G.W. "Castle" hauled the train to Llandrindod but limited clearance prohibited its use beyond that place.

After performing the opening ceremony at Claerwen, the Royal party rejoined the train at Llandovery, which then ran via the Llandilo - Carmarthen line to Milford Haven where the Royal Yacht lay at anchor, ready to begin a cruise into Scottish waters.

The engines were 8309 and 8707 working the train and 8330 as stand-by.

Apparently, a fourth 8F was also CWA fitted to cover the Grove's visit to Nottingham(?) although possibly merely to steam heat it while stabled. I have no evidence of any of this other than a fireman's statement that the steam heat valve was present in the cab when he worked the engine while at Burton. Why it needed an 8F to provide the steam with so many already equipped Black Fives around isn't explained.

 

I assume that first choice for passenger work were those starred engines balanced for higher speed running although I know I later years that couldn’t be relied on. Were those with the single cone ejector banned from fitted work as I assume it would take a fair while to blow the brakes off?

 

Theoretically, only starred engines would be diagrammed to passenger work but I suspect that in times of crisis, if it would roll, it would go. I'm not aware of any restrictions based on the ejector type. Realistically, the large ejector was used initially to blow the brakes off but after that the small ejector was sufficient for the needs. You wouldn't need the large one at a station stop, for instance, and on the move the driver wouldn't normally reduce the vacuum below ten inches anyway.