Longshot, but is that by chance Edwort's Robust Porter. In a few years of brewing that is usually, for reasons I cannot fathom, always an insanely violent fermentation.
End result never disappoints though.
At least you were smart enough to forsee the need to use the blow off. When I made my stout I used an airlock and boy what a mess. All over the ceiling, firances car and garage floor. Took a while to clean everything up. Needless to say, now I use blow off regularly.