Of course you can, Stan. Just go back a few pages on the index page.
It's the old salvor's trick of adding up the horsepower of absolutely everything on board to show how powerful the latest tug is.
For LONDON, the main engines are indeed rated now at 13500bhp/9930kW maximum continuous rating (mcr). I don't have horsepower figures for the auxiliaries and generators, but in kW are shown as 1 x 218, 3 x 581, 3 x 560. That lot adds up to 13571kW, or about 18500bhp. And then there are diesel pumps, bowthruster etc etc to add in. The original main engines rating may have been higher - so 22000bhp looks like the kind of figure they might well have claimed.