You bring up a very good point. It seems that I have missed out detailing the exact force of the explosion in this article. I will amend this.
In terms of comparing the Halifax explosion to the RAF Fauld explosion. The Halifax explosion had the equivalent force of 2.9 kilotons of TNT whereas the RAF Fauld Explosion had an equivalent force of 2 kilotons of TNT.
Although still very powerful (probably the second biggest non-nuclear explosion although I haven't done enough research on this to say this with certainty) it does not beat the power of the Halifax explosion.