Steam tug Challenge
from London

MPZB	33.5	8.0	4.3	212		845	10
Built in 1931 by Alexander Hall & Co, of Aberdeen
Call sign	Measures in meter			Tonnage		Engine kW	Speed Knots
Call sign	Length	Beam	Draught	Gross	Net	Engine kW	Speed Knots
Scotch marine boiler with three oil-fired furnaces. 13,8 bar.
Triple expansion engine with Stephenson's link-motion.

Steamship Challenge moored
Steam tug Challenge moored.

The engine room aboard steam tug Challenge

Steamship Challenge steam engine
Steamship Challenge's triple expansion steam engine with Stephenson's link-motion.

The steam tugs stokehold where the stoker attends the Scotch fire tube boiler's three oil burners.
One of the Todd natural draught pressure atomising burners is visible down left on the picture.