No. They're not articulated - each has two bogie trucks. It's a rake
of several wagons with a standard coupling on the outside to couple
with an engine of a similar rake. Between the bagons is a different
kind of simpler coupling more like a drawbar that is not designed to
be separated in service.
I've never heard them called articulated before, they're separate
wagons with standard couplers on the outside of the rakes,
And many unit coal trains have cars fitted with special couplers (so
they can be rotated) or bottom hatches (so that they don't need manual
opening) in order to unload them without uncoupling, or without
stopping.... Now that's an operation I'd like to see done in HO. ;-)
On 8/29/2009 11:39 AM Christopher A. Lee spake thus:
I find this hard to believe. After all, in the US, airbrakes were
standard well before the end of the steam era, and I think that the rest
of the world wasn't that far off in adopting them either. (Not sure of
exact dates, and sure that others will give the correct info here.)
Not that there aren't those who model pre-airbrake eras; more power to
'em. But I think it's safe to say that *most* of us model times when
trains had airbrakes (and trainlines) as standard equipment.
By the way, I think you're making waaaay too much of the OP's perceived
difficulties with English. His writing seems perfectly clear to me.
Found--the gene that causes belief in genetic determinism
On Sat, 29 Aug 2009 15:23:45 -0700, David Nebenzahl
It's fact though.
Most steam era goods wagons were un-braked apart from a handbrake
lever. The trains trundled along pretty slowly. When they had to go up
or down a hill, the brakes were pinned down to prevent running away,
and thengine dragged the wagons against the friction of the brakes.
Rather like driving a car with the handbrake on. The wheels would
still go round but it took a lot of power.
There were vacuum braked freights which were faster but there were
less of these. Typically for perishable goods.
Coal was probably the highest volume freight traffic. Prior to WW2 the
railway companies could provide wagons at a daily rate, but because
these would spend so much time at the colliery or the coal merchant,
it was cheaper to own or lease your own.
The average coal merchant wanted a load that would fit in a short
wheelbase 4-wheeled wagon. The GWR and other lines tried to streamline
things with larger wagons but these were too big for the customers, as
well costing more to hire per day.
The 4-wheel wagons were built as cheaply as possible, and were little
more than mobile coal bins. The customers disn't want anything more
As previously pointed out, the only brake force for these trains came
from the engine and tender, with a screw-down hand brake on the
guard's van at the rear.
During WW2 all these were commandeered for the war effort.
Nationalisation came after WW2 and while there were modernisation
plans, things carried on pretty much as before.
If you don't believe me, try to find brake hoses on this wagon built
This was larger than most because it was internal use, for locomotive
coal. The average coal merchant still only wanted half that load.
Air brakes came into general use in the UK after the end of steam.
Passenger trains and fast freight used vacuum brakes. In the early
1980s a train I rode from Manchester to London was very late because
the dual fitted (vacuum and air) failed, and the first replacement
they sent only had air. This was the Manchester Pullman whose stock
had been built in the 1960s
During this era newer passenger stock was air braked and older vacuum,
with some of the older having both. Many nut all locomotives were dual
braked. Incidentally the train I mentioned was the Manchester Pullman
and the carrengines but not all dual braked, a
But coal, mineral and other unfitted freight ran until well after the
end of steam.
Here's a diesel brake tender to brovide extra braking force for a
diesel engine pulling an unfitted train of 10-ton mineral wagons..
Nope. He's absolutely correct. The majority of British freight trains ran
with only the locos brakes, the hand brake on the tender and the guard's
hand brake in the brake van at the rear of the train. That's why most UK
trains ran at less then 40 mph, because all the braking was in the loco and
the weighted brake van at the rear.
Umm, not really! Many freight trains, but more especially coal, were often
built up through accessing many short branch lines, collecting from, and
delivering to, other short branch lines, throughout industrial districts
or coal mining districts, with difficult access. They were often very
The merry-go-round coal trains for power stations came very much later
with longer runs, collecting from fewer and much larger coal pits. (I
worked on some of the coal handling plants which received these trains)
The system was and is very efficient.
If I may take the opportunity and go slightly OT, I have never been able
to understand US practice with coal drags, where as many as 100 wagons (?)
were coupled (10,000 tons ?) being typical but frequently ran at well
below locomotive economic running speed, walking speed no less, and, I
understand, often stalled. How come? This has puzzled me for a long time.
I have several CD's of C&O showing Allegheny H8's just crawling with mile
long coal drags!
Any explanations, please.
I mean, one could equally ask, why choose the Mallet system as opposed to
the Beyer Garratt?
Ore trains in the Missabe Range were in that range, too. That's the
reason for the Yellowstone, a 2-8-8-4 that had greater weight on drivers
and greater tractive effort than the Bog Boy (which was heavier overall.)
Here are some of the things I've figured out from my reading, and from
recall of the thermodynamics course I took many years ago. I don't claim
it's a complete explanation, but it's certainly part of it.
Those locos were designed as "drag" locos, for low speed and heavy
trains. The economics of steam locomotive speeds are complicated. The
drag locos were designed to be most economical at low speeds, in the
15-20mph range. Articulation was used because you essentially get two
engines for the price of 1-1/2, with a single crew. And as with all
engines, bigger means more efficient.
Mallet vs Beyer-Garratt is a "cultural" difference, heavily influenced
by NIH syndrome. Also, IIRC, Beyer-Garratt was patented, while the
Mallet was just a compound articulated loco, anybody could build one
without paying royalties. A lot of so-called Mallets were simple
There are other aspects to the economics of trains. The sheer amount of
coal to be hauled is one. The logistics of managing many short, lighter,
faster trains are complex compared to fewer, longer, heavier, slower
ones, and it's worse when they run on the same tracks. Railroads hate
mixing freight and passenger trains for this reason. It requires extra
tracks and passing sidings, more complex signalling, and so on.
By the time all these and other factors are balanced against each other,
running a heavy trains at less than the engine's most economical speed
was a minor cost compared to others.
I'm sure there are many things I've overlooked.
Yes, they were big weren't they. As I understand it the Big Boy wasn't
especially efficient, or wasn't run efficiently, and threw a lot of coal,
unburnt, up the stack. The fuel was just so cheap that it didn't matter.
Sometimes, it depends how you run them.
I'm sure your right!
True! That must have influenced decision making.
The early one's, yes.
I think that 'all' the later ones were, weren't they?
That's certainly true in the UK.
But, weren't many US long haul tracks virtually dedicated solely to coal
and/or ore, though?
ie. fuel was cheap at the time. But, as an admirer of the engineering of
both the Yellowstones and the Lima H8's, I am aware that the economical
running speed of both was far higher than what was current running
practice. I mean, CD's showing Yellowstones on the Doluth Missabe and Iron
Range show them to be really shifting, whereas the H8's were capable of
far higher speeds than was normal practice which appeared to be slow coal
drags. I think that I am correct in thinking that C&O didn't really know
the H8's full capabilities until it was far too late to utilise it.
Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here.
All logos and trade names are the property of their respective owners.