Spam cans on branch lines

[muggins]

As I understand it, I could run a West Country or a Battle of Britain on a Southern branch line with just one or two carriages without invoking Rule One. And it could even run tender first. What I've never understood though, is - how come? How would that actually come to pass? If the one or two carriages were the back end of say a London train, how come there was a spam can at the detaching station with nothing else to do but run a couple of carriages up a branch (and presumably back)?

Or were they perhaps not actually as "main line" as I always thought they were?

[stuartp]

The Southern ran its principle summer seaside traffic in portions so the train would shed coaches in ones and twos at junctions along the way to be tripped down to the terminus. I don't think they would all have a spam can but those going all the way might if thats what had worked the train down. Others might depending on what was available, a short trip down a branch line and back was a useful 'filling in' turn for a loco which had brought a train down earlier in the day and was awaiting it's back working.

As for tender first, if there was no turntable at the terminus or it was too short for a mainline loco, then it went back tender first, simple as that.

[muggins]

Cheers Stuart. Maybe I need more coffee, but I'm still not sure I get this. Say an express leaves London bound for somewhere in the West country. On the way, it stops at a junction and two carriages are dropped off the back to go up the branch to Mud-On-Sea, which they do behind a spamcan. Is the spamcan available because the train it was working terminated at the junction and there's nothing else for it to do until it works the return back to whereever it came from?

[SRman]

Spam cans (light pacifics) were officially mixed traffic locos, although they were treated more as express passenger types- Their original rating was 6MT but was later amended to 7P 5FA. Their axle loadings were designed to be acceptable on all but the lightest of branch lines - something that couldn't be said of the slightly heavier rebuilds.

They were certainly overpowered for branch line use, but part of their remit was to replace a motley collection of pre-grouping locomotives of all types, including many 0-6-0 types that were used on branches. In fact, some of those types survived for longer, but the Bulleids still ended up on some branch line duties from time to time.

[stuartp]

Is the spamcan available because the train it was working terminated at the junction and there's nothing else for it to do until it works the return back to whereever it came from?

Potentially yes, there was nothing like the widespread intensive use of assets you see nowadays, indeed you can't use a steam loco that intensively as it needs coal and the fire cleaning every few hours. The sort of diagrams you see today where an HST/800 etc leaves a depot at 5am and doesn't come back in til midnight were few and far between. Seasonal traffic involved even more hanging around between turns.

I'm not an expert on the Southern, my comments are based on what I've picked up and knowing that the ACE had the largest proprtion of brake coaches of any long distance express (because every portion needs a brake van). However, for an example further afield the Costorphine branch in Edinburgh was regularly served by A2/3 pacifics because it got them out of the way of Waverley station and St Margarets shed while they were waiting to work back south in the afternoon.

[6C]

Basically as Stuartp says a train for the 'withered arm' such as the Atlantic Coast Express would leave London as a 12-15 coach formation and shed portions of 2-3 coaches at Exeter, Yeoford, Okehampton, Halwill Junc. and Wadebridge - so you would still have the large main line loco still at the head at the final destination.

Vice versa, the large loco would start the process in reverse from Cornwall and Devon with only 2-3 coaches initially...adding portions as it arrived at junctions - until by Exeter it would be the full formation..

[Bigmet]

Cheers Stuart. Maybe I need more coffee, but I'm still not sure I get this. Say an express leaves London bound for somewhere in the West country. On the way, it stops at a junction and two carriages are dropped off the back to go up the branch to Mud-On-Sea, which they do behind a spamcan. Is the spamcan available because the train it was working terminated at the junction and there's nothing else for it to do until it works the return back to wherever it came from?

The usual operational pattern was that the train sections dropped off en route, to be worked down various branches, would get the local power on a regular booked turn; and there are your famous antediluvian Southern tanks like M7s, Terriers, Adams Radials, working an all stations to Duckage, Slyme Boggis or Dude. Now, betimes there might be a spamcan lurking at such a location, all sorts happened on the steam railway, and it might be put on such a turn.

BTW, always 'down' a terminating branch when travelling to its terminus. (There were one or two weird railways that never quite grasped that one always goes up to London, but these eccentricities may be ignored.)