Section III, 1918 [31] Trans. R.S.C. 



Some Notes on The Halifax Explosion 

 By Howard L. Bronson, Ph.D., F.R.S.C. 



(Read May Meeting,- 1918.) 



The explosion which wrecked Halifax on December 6, 1917, 

 undoubtedly far surpassed all previous explosions both in its destruc- 

 tive effects and in the quantities of explosives involved. Although 

 facts and figures concerning the explosion are necessarily incomplete 

 and in many instances not very rehable, still it seems desirable to 

 gather together and place on record such information as is available. 

 The thermo-chemical and other theoretical and experimental data 

 used in this article were obtained from Marshall's "Explosives," 

 Brunswig's "Explosives," Molinari's "Chemistry," and from Mr. W. 

 C. Cope, explosives chemist of the E. I, duPont-deNemours and 

 Company. Mr. Cope was called to Halifax as the explosives expert 

 at the investigation into the disaster, and was good enough to furnish 

 me certain facts and figures. 



The following is a brief account of the events leading up to the 

 explosion. The munition ship Mont Blanc, loaded with some 2,500 

 tons of high explosives and with a deck load of monochlorbenzene, 

 was about to enter the Narrows of Halifax Harbour when she collided 

 with the Imo in such a way that the bow of the Into was driven well 

 into her side. The heat developed by the collision was sufficient to 

 ignite either the monochlorbenzene or the picric acid, the latter being 

 the more probable according to Mr. Cope. The fire burned for 

 nearly 20 minutes, during which time the Mont Blanc drifted close to 

 pier 6 on the Halifax side of the harbour and apparently grounded 

 just before the explosion. During this time and previous to the final 

 explosion there were at least three small explosions, apparently 

 caused in the drums of monochlorbenzene. 



Before describing or discussing the effects of the explosion, it 

 would seem of interest to consider with some care the magnitude of 

 the explosion in terms of the amount of energy liberated and the vol- 

 ume of gas formed, together with the probable temperature and pres- 

 sure of the gas. In order to determine these various quantities the 

 following assumptions have been made: (1) that the entire cargo of 

 explosives entered into the detonation. This was evidently not the 

 case, for it was burning 17 minutes previous to the explosion, and, as 

 we shall see later, there is some evidence to indicate that part of the 



