UP Challenger

The normal (European) use of the "+" is for locos where individual loco units are perminantly coupled together, such as the Swiss Ae 8/14 - two complete locos but some (control) equipment is not duplicated. A US example might be the earliest F units as originally delivered ie Bo'Bo'+Bo'Bo'. for an A+B "unit". The apostrophes show a separate flexible frame, so the SP AC becomes a 4'8'-8 2'. (the second set of drivers has no apostrophy because they are mounted on the rigid main frame)

Regards, Greg.P.

That may well be its purpose, to you, but all too often it is merely indoctrination into the accepted thought patterns.

John H

In that case the notation would be 4'8-8'2'. The second set of drivers are articulated, not the first.

The convention in the US is to count from the front of the loco. And as far as I can make out, that convention also applies in Europe...

Wrong! The convention is to count from the "front" of the loco to the "back".

And what would they be? Steam locos with Franco-Crosti boilers, where the chimney/stack/funnel is halfway down the side of the boiler? Double Fairlies or Pechot-Bourdons, with two boilers either side of a common firebox? Kitson-Meyers with one boiler, but two chimneys, one at each end? Your "convention" doesn't work with any of these.

The Italians described their Gr670 class engines as 4-6-0s, not

0-6-4s, the SP described their engines as 4-6-6-2s and 4-8-8-2s, so where is the evidence that the convention is to count wheels fom the chimney end?

The European convention is to count from smokebox to firebox. The only European "cab forwards" I can think of were the German BR 05 (4-6-4 so it doesn't matter) and the Italian 4-6-0 or 0-6-4 express loco. (I can't remember the class offhand)

Regards, Greg.P.

Good point! :-)

That would definitely be an exception!

You should get the same result counting from either end!

Nor does yours!

That's the one - they counted from the chimney end.

The Italian loco you mentioned above.

Er, to me it looks like a _different_ convention, is all... :-)

Good point!

How about this: why can't we accept the "convention" of the country in question? Here in the US, that means count from the designed "front" of the locomotive, while elsewhere, it means the stack end.

Since the SP NEVER referred to the AC-12 (for example) as a 2-8-8-4, and ALWAYS as a 4-8-8-2 (in the original Whyte scheme), that's good enough for me.

If the same loco were running down under, I'd be fine with you calling it whatever you wanted.

Agree. Note that the US "bible", the Locomotive Cyclopedia, states that the Whyte classification starts at the "pilot or head end of the engine". It also makes sense to base the system on the usual front of the locomotive rather than the smokestack as lead and trail trucks are functionally different, and it can be useful to know which truck is performing which function. Lead trucks almost always have lever or roller arrangements which increase the load on the leading axle(s) as the truck moves off-center as part of the design to help guide the locomotive into a curve. Trailing trucks most often use rockers or rollers which keep the load on the rear axles constant as the truck moves off center. I don't have detailed drawings of the trucks under the cabs of the Espee cad-forwards, but from their external appearance, they are more like the outside bearing lead trucks on some 4-8-4's than they are like a typical Commonwealth firebox-supporting trailing truck. Geezer

If it's a convention, do we get to wear funny hats?

Oh - never mind: we already have funny hats, and vests to go with them.

I'm fine with that - without having made my first comment I would never have realized that the US/SP convention was different.

I think we're going to have some problems adapting it to 3'6" gauge and our smaller tunnels! :-)

Regards, Greg.P.

Snipped!

You could always put a TBM in front of it.... The first time thru is a little slow and rough, but after that's over you shouldn't have any clearance problems. :)

But imagine the photo opportunities!

I'd love to see the sole remaining SP cab forward in steam again; won't ever happen, though: the Republic of California has her stuffed and mounted in Sacramento, where you can't even get decent photos.

That's a shame! Are any of the US Mallets running these days? A 600mm gauge Decauville 0-4-4-0t just wouldn't give the same effect!

Regards, Greg.P.

The last time I was in that part of NZ, there was an Alco 2-4-4-2 running at Glenbrook. Is it still operable?