Re: (TGR) L and M class Garratts

["Derick Wuen" <cullend@webone.com.au>]

I hesitate to enter a debate on "unsuccessful" steamers after the D58
exchanges, but here goes anyway....

Deeble seemed very pleased with M and L classes after adjustments to
drafting arrangements and smokebox details. See "good press" coverage from
Launceston Examiner of 30/11/1912, reproduced in "Beyer, Peacock Locomotive
Builders to the World", Hills and Patrick, page 147. In summary, pulled
double the weight trains for only 25% increase in fuel.

The (first) Campania disaster in 1916 involving the M was blamed on "fast
speeding" officially, but conspiracy theorists blame the track, based on the
poor condition of the rail on the outside of the curve and the fact that the
rear engine seems to have derailed first.

Whatever the cause, the M's were relegated to freight, and there were no
repeat orders for Garratts, R and Q classes being preferred.

I favour the stuff-up over the conspiracy as an explanantion for most
unsatisfactory things. Thus looking at an 8 cylinder express loco design for
a 1067mm gauge railway built to, well, err light standards smacks of a
stuff-up to me. Remember, the M and L were amongst the very first Garratts
built, and communications had every chance of being garbled between Tassie
and Manchester..... easy to misinterpret an order involving 4 cylinders per
engine as being 4 cylinders for each engine unit as opposed to 4 cylinders
per each locomotive?

Preparing a Garratt for the road is a lengthy task... not only are there 2
engine units to lubricate and inspect, but there are articulation pivots and
bearings as well. Normally all this stuff is accessible from ground level
and outside the locomotive, a big plus for the Garratt. But now add two
inside connected mechanisms between narrow gauge frames for an M class. ...
you now require a pit and a midget to complete the task.

I think the same result could be achieved with less machinery and
preparation time with a 4 cylinder locomotive which would have ridden almost
as smoothly as far as the crews were concerned. Smooth riding is another
plus for the Garratt design, and no need for more naturally balanced 8
cylinders.

References (Durrant, Cooley) put down "failure" to speed; I think the M's
were just too sophisticated, through miscommunication of design specs, for
requirements and track infrastucture, and the L's reputation suffered by
contagion following Campania.

One wonders what might have been if an M had been let loose on some of the
heavily engineered 1067mm railways such as in South Africa or modern day
Queensland.




John Dennis wrote in message
<08d43c59.6f4330ab@usw-ex0104-026.remarq.com>...
>In article <8h20ft$dlo$1@nnrp1.deja.com>, The Oracle
><ianadunn@yahoo.co.uk> wrote:
>>
>>
>>> John Dennis wrote:
>>>
>>> > Bad form to follow-up your own posting, I know, but a little
>>> > research has discovered that the M class were 4-4-2+2-4-4
>>> > 8-cylinder compounds.
>>
>>Correction here: the M class were 8-cylinder simples (2 x 4-cyl
>>engine units). The mechanism was not complicated, since the
>>inside valves were actuated by simple rocker mechanisms from
>>the outside Walschaerts-operated valves.
>
>My mistake.  I saw the annotation "8-cylinder" and made an
>assumption they were compounds.  In fact it turns out there were
>only two designs of compound garratts.  The very first garratt
>built, 2' gauge K class of Tasmania, with 2 locomotives, and the
>Burma Railways class GA II of 1927 which had bua single
>representative.
>
>It would seem that weight of opinion is along the lines of power
>and speed.
>
>Cheers...JD
>
>
>--
>John Dennis
>Home of the Dutton Bay Tramway
>http://members.optusnet.com.au/~jdennis/dbt.html
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