It is mostly smooth gravel fireroads with some rougher sections ( including a few notable downhills) some road sections and some man made multi use paths around kielder water.
There is no single track or anything technical, in fact they have taken out a few of the more technical sections over the years and for this year they have removed a ford and a long climb after the 100k feed zone.
The whistle and blanket are for emergency only, but you will never be alone due to the sheer number of riders. Just think of it as a 60k ride followed by a stop, then a 40k ride followed by lunch, then a 75k spin with hot cheesy potatoes and coffee at the end, and finally a 20-25k spin to the finish with a beer waiting for you