This made me curious about how the HET compares to something like a Kenworth T800 with a similar wheel base and to other mv.
The TM_9-2320-360-10 lists a 67.9' turning radius for HET without trailer, wheel base appears to be 215". The Kenworth book didn't list any tridems, but heavy tandems with 220" wheelbase had turning radius of 44'. I thought maybe the M920 would be better with the airlift axle, but it is actually worse, so the M1070 was a pretty big improvement.
The information below is from a 2011 SS thread posted by runk http://www.steelsoldiers.com/showthread.php?68712-M916-M920-wheelbase The information available on this site is amazing! I just added a couple of dimensions for the Kenworth & HET.
from TM 9-2320-273-10
Minimum turning diameters, curb to curb, are listed below:
M915 53.5 feet (16.31 m)
M916 80.0 feet (24.4 m)
M917 89.5 feet (27.3 m)
M918 80.0 feet (24.4 m)
M919 89.5 feet (27.3 m)
M920 89.5 feet (27.3 m)
M1070 67.9 feet
T800 44.0 feet
DIMENSIONS
Length (overall, less pintle hook and lifting shackle)
M915 268.50 in. (6.82 m)
M916 294.30 in. (7.48 m)
M917 350.60 in. (8.90 m)
M918 350.60 in. (8.90 m)
M919 374.40 in. (9.51 m)
M920 319.30 in. (8.11 m)
Width (overall)
ALL 96.75 in. (2.46 m)
Height
M915 134.63 in. (3.42 m) (over stack – empty)
M916 142.00 in. (3.61 m) (over stack – empty)
M917 141.00 in. (3.6 m) (overall)
M918 142.00 in. (3.61 m) (over stack – empty)
M919 142.00 in. (3.61 m) (over stack – empty)
M920 142.00 in. (3.61 m) (over stack – empty)
Height (reduced, no load)
M915 114.63 in. (2.91 m) (over horns –empty)
M916 128.00 in. (3.25 m) (over horns – empty)
M917 Not reducible
M918 128.00 in. (3.25 m) (over horns – empty)
M919 128.00 in. (3.25 m) (over horns – empty)
M920 128.00 in. (3.25 m) (over horns – empty)
Ground Clearance (under rear walking beam bracket) (empty)
M915 10.25 in. (26.03 cm)
M916 11.62 in. (29.51 cm)
M917 12.00 in. (30.48 cm)
M918 11.62 in. (29.51 cm)
M919 12.00 in. (30.48 cm)
M920 11.62 in. (29.51 cm)
Wheelbase
M915 168.25 in. (4.30 m)
M916 186.00 in. (4.72 m)
M917 211.00 in. (5.36 m)
M918 186.00 in. (4.72 m)
M919 211.00 in. (5.36 m)
M920 211.00 in. (5.36 m)
M1070 215 in.
T800 220 in.