Model Forum / General / Railroads / September 2009

I found this translation of a paper Mallet himself gave in French, in
Railway locomotives and cars, Volume 65 from 1891

http://books.google.com/books?id=ivk6AAAAMAAJ

It's on pages 202-204.

There is a drawing of his first articulated locomotive, which it
interestingly calls the Decauville system (the builder).

He also refers to a paper from 1877 which I haven't found.

Incidentally, would his first locomotive, a rigid 0-4-2 tank engine
that was a 2-cyliner compound also be called a Mallet by the "logic"
that says only hic compounds should be called Mallets?

Even though it is the label given to both simple and compound engines
using the system of articulation he devised?

Cite. I have done so multiple times. You either will not or cannot.

Sure. That must be it.

And that neatly sums up your position:

(A) Pete is wrong.

(B) Any website Pete cites that says anything other than what you want
to believe also "got it wrong".

(C) Diebert and Strapac -who literally wrote the book on S.P. steam-
also somehow "got it wrong".

(D) So did the engine crews who worked the actual locomotives.

(E) The entire Southern Pacific railroad "got it wrong" as well.

(F) And you, who can seemingly provide no cites to back your claim,
are right.

So thanks for that clarification, because it tells us exactly where
you stand: In mid-air with no visible means of support.

And now I bid you a fond farewell.

~Pete

Oh dear! All this medieval, how many patentees can dance on the head of
pin, kind of argument  ...  come on guys, this is a hardly "The War of
Jenkin's ear" (see wiki.) is it! 8-)

However, I found the following on www.steamindex.com/people/cotengr.htm
which just might be of interest. I have no idea as to the extent of it
being right or wrong, though I don't suppose for one minute that it will
resolve any conflicts. 8-)

Mallet, Jules T. Anatole

Westwood, claims that Jules Anatole Mallet was remarkable amongst late
nineteenth century innovators in that he achieved a influential success
both in compounding and in a method for articulating the driving
wheelbase. The resulting Mallet articulated locomotive became especially
popular in the USA, where it attained great size. Mallet‘s ideas on
compounding inspired many subsequent designers to develop their own
compound locomotives, some successfully, some very unsuccessfully.

Mallet was born at Carouge, near Geneva, in 1837, and studied and later
taught engineering at the Paris Ecole Centrale des Arts et Manufactures.
He first attracted attention in 1877, when the Bayonne-Biarritz Railway
put two tank locomotives into service, designed according to Mallet‘s
two-cylinder compound system with a single high-pressure cylinder passing
its exhaust steam into a second, larger, low-pressure cylinder. The
Biarritz locomotives worked well, but like subsequent two-cylinder
compounds they tended to be unsteady at high speed, because one cylinder
exerted more thrust than the other. Mallet was unable to interest any of
the mainline railways in his idea. This lack of enthusiasm is not
surprising when it is remembered that even after compounding had been
adopted by many railways, it was never adopted by a majority. Those who
rejected the idea almost always did so on the grounds that any fuel
economies obtained from so-called double expansion were lost by the extra
complication of compound machines. This criticism of compounding would be
reinforced after superheated steam had shown another way of overcoming the
basic problem that compounding attacked: that is the condensation of steam
inside the cylinders which resulted from the fall in temperature as the
steam expanded. Compounding broke the steam expansion into two parts,
divided between two cylinders and thereby made it easier to cope with
cylinder wall condensation. Superheating raised the steam temperature so
that even after cooling it would remain higher than condensation
temperature. Ideally, from the point of view of thermal efficiency, the
most efficient machine would be one embodying both superheating and
compounding, and many such machines were built in the twentieth century.
In the 1870s, however, compounding seemed the only solution. Mallet
believed he had a workable compound system, but could not persuade French
engineers to try it.

However, the proliferation at that time of narrow-gauge light railways
gave Mallet another avenue of approach. These lines required more powerful
locomotives than their winding tracks could tolerate, and the only
solution seemed to be some form of articulated locomotive. Two
articulation systems were already fairly widely adopted. These were the
and the Meyer concepts, both of which embodied two pivoting engine units,
supplied by steam through pipes with flexible joints. These flexible
joints, so difficult to keep steamtight, were a weakness of these systems,
and Mallet believed he had a solution in his own system of articulation,
which he patented in 1884. Instead of two pivoting engine units, he had
just one, placed beneath the smokebox. A second engine unit was at the
rear, but this was non-pivoting. It was on this rigid rear unit that the
boiler was fixed. For Mallet, the important feature of this layout was
that it was a perfect setting for a compound system. Steam was taken first
to the high-pressure cylinders of the rigid rear unit, and then piped to
the cylinders of the leading pivoting unit for re-use at a lower pressure.
In this way it was only the low- pressure steam which passed through the
flexible steampipe joints, thereby easing the problem of steam leaks. The
first such Mallet locomotive appeared in 1888, being built in Belgium for
Paul Decauville. In 1889 Decauville‘s 60cm gauge line at the Paris
Exhibition carried more than six million visitors and assured the
continuing success of his enterprise. It also assured the future success
of Mallet‘s compound articulated locomotive, for it was on this line that
the first Mallet units made their debut.

The obvious success of these machines was followed by orders for similar
narrow-gauge units from many railways, at first with the same 0-4-4-0T
wheel arrangement but later in other versions. In the nineties the Mallet
tank locomotive was joined by the Mallet tender locomotive in Switzerland
and Germany.

1904 the Baltimore & Ohio Railroad introduced the Mallet concept to
America, ordering an 0-6-6-0 from the American Locomotive Company for use
on its Sand Patch incline over the Alleghenies. By 1911 more than five
hundred Mallets had been built for US railroads. During the First World
War the Virginian Railway brought the original Mallet concept to a peak so
far as size was concerned, ordering 2-10-10-2 units whose low-pressure
cylinders were 48in. in diameter. This Virginian design represented the
virtual limit of size for the conventional Mallet locomotive. The overhang
of the boiler at the front end on curves was excessive, and the low
pressure cylinders were so large that it was impossible to design adequate
valves for them, which meant that they worked efficiently only at low
speeds and long cut-offs.. Moreover, the 4ft diameter cylinders were the
biggest that could be accommodated on American railroads. For this reason
most subsequent American Mallet locomotives were simples, not compounds.
Later, American designers eliminated another fault which inhibited
high-speed running with Mallet locomotives. This was the rough riding of
the forward engine unit, which was only loosely attached to the main bulk
of the locomotive.

Eventually Jabelman of the Union Pacific modified the articulation and
applied a four-wheel leading truck to produce the Challenger  4-6-6-4,
which could run up to 80 mile/h. This type was developed into the 4-8-8-4
Big Boys, which are regarded as the most powerful locomotives ever built.
Although, at its peak of popularity, the Mallet locomotive was ordered by
railways in many parts of the world, it was only in America that it
retained its market up to the end of the age of steam.

Garratt form of articulation, developed later, was technically superior,
while many central European lines found that they did not really need
articulated types. As for Anatole Mallet, it is said that he did not
approve of the concept of the simple Mallet locomotive, as he had evolved
his system of articulation as a means of promoting his compound system. In
the twentieth century he was something of a grand old man of French
engineering, regularly contributing comments on locomotive matters to the
Memoires of the French society of civil engineers. He also designed the
original locomotives for the Lartigue monorail system. Relatively little
information has survived about Mallet the man, even though he was probably
one of the three most important post-Stephenson locomotive engineers.
Marshall noted that he died in October 1919..

Les Locomotives Articulees du Systeme Mallet dans le Monde A. E. Durrant,
The Mallet Locomotive On the compounding of locomotive engines. Proc.
Instn Mech. Engrs,

Cheers,

Brian

On 9/6/2009 7:06 PM Steve Caple spake thus:

OK. You can call it "ill-a-noise".

Decatur, huh? "Downstate" to me. I think the only time I was even near
there was when my dad took us to Springfield, Lincoln's log cabin and
all that, back in the 19-ought-60s, and to the Cahokia (sp?) mounds. Are
those around there?