Steam Locomotive Firebox Explosion on the Gettysburg Railroad ...

Figure 14. Water-glass tube.
b. Close the drain cock and open the
lower gage glass valve. Water should
return to the gage glass immediately.
c. Close the upper gage glass valve,
then open the drain cock and allow the
water to flow until it runs clear.
d. Close the drain cock and open the
upper gage glass valve. Water should
return to the gage glass immediately.
If the water return is sluggish, the
operation should be repeated. A
sluggish response could indicate an
obstruction in the pipe connections to
the boiler. Any leakage at these
fittings should be corrected to avoid
damage to the fittings or a false
waterline indication.
Although 49 CFR 230.40 requires that
water glasses be blown down, the procedure
for doing so is not given or specified in any
applicable Federal rules. Nor are any other
rules of the National Board Inspection Code
applicable by law or regulation to steam
locomotives not governed by the National
Board Inspection Code. The Gettysburg
Passenger Services employees did not have
any reference materials that explained the
proper method of blowing down a water
glass,
When Safety Board investigators asked
the first fireman to demonstrate the proper
method of blowing down the water glass, he
failed to demonstrate the correct method.
Similarly, the second fireman failed to show
and explain the proper method. He said he
had had no formal training on blowing down
the water glass, but that he had been shown
how to do it. When the helper engineer was
asked to describe the blow-down procedure,
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