Fusible plugs

NW Mailing List nw-mailing-list at nwhs.org
Thu Apr 4 14:49:08 EDT 2019


Not all engines had fusible plugs.  I have run engines with and without them.  I think it may have been a combination of railroad and manufacturer preference on whether to use them.Jason MaxwellSent via the Samsung Galaxy S7, an AT&T 4G LTE smartphone
-------- Original message --------From: NW Mailing List <nw-mailing-list at nwhs.org> Date: 4/4/19  8:00 AM  (GMT-06:00) To: nw-mailing-list <nw-mailing-list at nwhs.org> Subject: Fusible plugs Several people here have commented about fusible plugs. The enginesdescribed which did blow up ALL had the fusible plugs in them. Thosewere a part of loco boilers from as early as the 1830s from myresearch. I don't know (but strongly suspect), they were a requiredpart of all boilers but if not, they were at least widely used fromvery early on. 1830s references specifically mention them as lettingloose from poor management of water on the crown sheet. Better thatthan "boom" I guess.To reiterate though, Ed King's excellent article which he referencedearlier "Big Bang, No theory," relates what happens in a fraction of asecond when a boiler goes ka-plooey. And I suspect that for whateverthe reasons, the sudden expansion of water into steam didn't affordample opportunity of time for the plug to soften and release. Alsoremember that something like a cubic inch of water in a closedpressure vessel like a boiler will expand something like 1540 times inan instant, hence the big bang and fact that the containment vessel(boiler) doesn't have an endless expansion capability. I understandthat regarding steam, the safety factor was something like 4 before itwould let loose, nowhere near what actually they were momentarilysubjected to before the trip to the promised land.Thanks Ed.Bob Cohen________________________________________NW-Mailing-List at nwhs.orgTo change your subscription go tohttp://list.nwhs.org/mailman/options/nw-mailing-listBrowse the NW-Mailing-List archives athttp://list.nwhs.org/pipermail/nw-mailing-list/
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