There seems to be a "crossover" between steam engine and band organ
admirers, so I was not surprised to see the recent entries on steam.
Having owned and operated two Frick steam traction engines and a
Kelly-Springfield steam roller, over a period of years, in addition
to using small miniature steam engines in the physics classes I taught,
perhaps I might mention a couple of items that have been overlooked.
I know this is not the Steam Engine Digest, but to some there is no
sweeter music than a three chime steam engine whistle at about 150 psi.

In regard to the heat pellets used in the miniature engines, they
differ in BTU content and the amount of time they take to reach their
maximum heat.  Using Sterno or some of the larger British pellets will
melt the solder joints on some small boilers.  Most miniature engines
do not have soft plugs like the real ones so, as mentioned in the
earlier articles, an explosion will result.  A good basic rule is
to watch the water level and if it is low and falling fast, get rid
of the fire and get back.  Also remember that even most full size steam
engines can be run on air if you want a very safe, but not powerful
result.

This brings up the second matter.  It was stated in an earlier MMD
article that the tragic engine explosion at Medina, OH, was caused by
bad maintenance, which was not the major factor.  It is believed by all
experienced engine men I have talked to that the operator allowed the
front wheels of the engine to roll into a depression thus allowing the
water, which was already too low, to move forward in the boiler and
allowing the red-hot boiler crown sheet (directly over the firebox)
to have no water above it.  The mistake was already made so even if
water had moved back over the crown sheet it would have flashed into
superheated steam in great volumes that no safety valve could have
handled.  In modern terminology, "pilot error".

I would publicly like to thank the late John Holp and the Holp Family
of Lewisburg, OH, for taking lots of time to teach me what to do and
not to do with my engines many years ago.   I remember him saying many
times, "Always watch your water gauge, and back the damn thing down the
hills."  Its unfortunate that the Medina operator did not talk to John.

Best of Luck
Jim Welty

 [ Thanks for the safety information, Jim.  This discussion thread
 [ is published in MMDigest is because steam powers calliopes and
 [ small engines to run orchestrions.  The safety of steam-powered
 [ musical instruments is the important issue here, not the chime
 [ whistle nor the beloved cloud of steam.  -- Robbie