I just used 1318 (london III) in an Old Ale. I tried to find more info from brewers who have experience with this yeast. Couldn't find much.
I got obvious fermentation after 12 hours. I pitched at 75* and quickly cooled to 61*. 36 hours later woke up and krausen was pushing through the airlock. The temp was at 63* The lid was lifting up s$&t and I have go to work. I put on blow off, didn't help much. Cooled back down to 61*. No more blow off or lifting lid.
That was yesterday. This morning again back up to 64*, same thing lid lifting, blow off is bubbling this time.
Long story short this yeast is very finicky with temps. I am using water bath method for cooling, keeping exact temps are difficult. I would almost double head room for this yeast. I knew it was a true top cropper, but under-estimated the room it would take.