[PRCo] 1927 Manchester Gas Explosion

[Fred Schneider]

Guys:
The message below came from Dick Hasselman down in Sanabel Island, Florida.   Dick is a railfan who grew up riding Connecticut Company trolleys as a kid then worked his way up in the railroad industry finally retiring from a lofty position in Philadelphia as Conrail Vice President - Operations.   He isn't part of this list but if anyone makes a significant comment, I will be happy to forward it on to Dick.   (He is receiving this by blind carbon).

Dick:  Pittsburgh Railways is a address list of guys interested in western Pennsylvania trolleys run by Derrick Brashear, a distant relative of that famous astronomer John Brashear who built the original Allegheny Observatory on the campus of Western University of Pennsylvania, later renamed University of Pittsburgh. 

The Post Gazette used a generic streetcar picture for the image of the car lost in the accident.   If memory serves, it was the first single-end low floor lost.  I think it was a 5100 class.   

Fred Schneider


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Art,
 
I was less than one year old when this explosion occurred in Pittsburgh, so if I heard of it, it did not last with me until now.
 
This type of “gas holder” [called “gasometer”] was found in every city which had gas pipes in its streets, to supply homes and businesses with gas for lights and cooking.  Most of that gas was made by the local gas companies, and was actually Carbon Monoxide, which would explode only when there was a mixture of a small amount of gas in a large amount of Oxygen [air].
 
That gas pressure was very low, so it was stored at low pressure in gasometers, which could change their size to conform to the volume of gas they contained at any one time, without raising pressure.  Those were made of a series of “sections” [concentric rings of decreasing diameter like a telescope], with the smallest section in the center, having a roof.  Each section had a pocket around its bottom circumference, full of water, into which the next [smaller] section fitted, creating a seal against leakage.  And the bottom section had brackets around its top edge, which had wheels which ran along a vertical track as that section rose.  This can be seen in the photo.
 
Of course, the water in these pockets had to be heated in winter, to prevent freezing.  So, in later years, “waterless holders” were developed, which were like a giant piston in one closed building.
 
Next, when city gas was changed to methane, under pressure, all this became obsolete, because gas could be stored in pressure-vessels, and these old gasometers were removed.
 
Back to this explosion:  While the gas holder may have been “empty”, it is clear that enough gas remained in it, with enough air, to be an explosive mixture.  So the workers’ torch lit it off, with deadly results.
 
Thanks for sharing the photos.
 
Dick H
 
 
The historical video, courtesy of The Pittsburgh Post-Gazette, is at:
 
http://bcove.me/2sig61jh