score:8
I'm not sure there was a 'typical' speed. Most that I've read about have a speed in the range 9 - 11 knots. Some examples include:
The tramp steamer SS Monarch was launched in 1885, and had a design speed of approximately 10 knots.
The SS Daleby was built in 1900, and had a speed of 9.5 knots.
The Sizergh Castle was launched in 1903, and had a speed of 9 knots.
The SS Sutherland was launched in 1918, and had a speed of 11 knots.
The MV Silver Fir was launched in 1924, and had a speed of 10 knots. The Silver Fir was sunk by the German raider Gneisenau.
The SS Hartismere was built in 1933, and had a speed of 11 knots.
It may be worth noting that the design for the Liberty Ships evolved from the design of
"... a simple ship originally produced in Sunderland by J.L. Thompson & Sons based on a 1939 design for a simple tramp steamer"
Liberty Ships had a speed of 11–11.5 knots.