F stood for Frank (Full name Sidney Francis) - he was a noted powerboat engineer and also raced them. Rumoured to have been killed in a World War 1 naval accident, but actually survived the war and settled in California where he became a mining engineer and owner of a number of clay mines on the border with Nevada. He was also a rancher. Longtime resident of Portland, Oregon, whilst racing. Bar his Indianapolis foray, Brock's main year of racing was 1912 as Spencer Wishart's riding mechanic.

Biography last updated 14 Apr 2026