Having been towed up the outer Thames estuary by a genuine TID, I can tell you the only noise heard was the screw wash and the rhythmic gentle thump of the boiler feed pump. Steam engines are by their nature quite, when I served in the St Margaret's, I used to go down into the engine room and talk to the engineer alongside the main engine on full power and we spoke normally if we were in the wardroom, the only noise was the low rumble from the main bearings. I think you guys get confused with diesel engines. In fact not long ago I saw a brilliant model of a Gravesend steam tug, I was confused because it had a noise maker which was a good reindetation of the old long stroke Bolinger marine disel engines.
David