C.M.R. 29, 250, Bureau of Motor Vehicles, ch. 170, app 250-170-A
Approved configurations
(All axle spacing dimensions are axle center to axle center unless otherwise indicated.)
6-AXLE TRACTOR-SEMITRAILER VEHICLE
AT 108,900 LBS. GVW
DIMENSION LIMITS
Overall Vehicle Length:
If the semitrailer is less than 48 feet long - maximum 69 feet
If the semitrailer is 48 feet or longer - maximum 74 feet
Vehicle Width: 8 feet 6 inches maximum
Vehicle Height: 13 feet 6 inches maximum
(load may extend an additional 6 inches)
Tandem Axle Spread: 4 feet minimum to 8 feet maximum between axle centers
Triaxle Spread: More than 8 feet but less than 12 feet between centers of the extreme axles in the triaxle group
Semitrailer Length Limits:
Overall Length Including Load - 53 feet maximum
Wheelbase (Kingpin to center of rearmost axle)* - 43 feet maximum
Kingpin Setback* - 3 feet 6 inches maximum
Rear Overhang (Center of 5th axle to rear of semitrailer)* - maximum of 35% of wheelbase length
Center of rearmost axle of tandem to center of rearmost axle of triaxle**- 38 feet maximum
* Applies if semitrailer length exceeds 48 feet
** Applies if semitrailer length is 48 feet or less
WEIGHT LIMITS
Gross Vehicle Weight: 108,900 pounds
Steering Axle: 600 lbs. per tire inch; maximum 12,375 pounds.
Tandem Axle limit: 40,500 pounds
Single Axle in Tandem: Maximum of 60% of tandem weight
Semitrailer Tri-axle limit: 58,500 pounds
Single Axle in Triaxle: Maximum of 40% of triaxle weight
8-AXLE B-TRAIN DOUBLE VEHICLE
AT 137,700 LBS. GVW
DIMENSION LIMITS (Canadian limits in italics - not defined in ME law.)
Overall Vehicle Length: 82.02 feet
Vehicle Width: 8 feet 6 inches maximum
Vehicle Height: 13 feet 6 inches maximum (load may extend an additional 6 inches)
Box Length: 65 feet 7 inches maximum
Tandem Axle Spread: 4 feet minimum to 8 feet maximum between axle centers
Triaxle Spread: More than 8 feet but less than 12 feet between centers of the extreme axles in the triaxle group
Lead Semitrailer Length Limits:
Wheelbase (Kingpin to center of triaxle group) - 20 feet 6 inches minimum
Kingpin Setback - 6 feet 7 inches maximum
Fifth Wheel Position - No more than 1 foot behind the center of the rearmost axle on the semitrailer.
Second Semitrailer Length Limits:
Wheelbase (center of rear axle of triaxle to center of rear tandem) - 20 feet 6 inches minimum
Interaxle Spacings Betweeen Axle Centers:
Steering Axle to First Axle Front Tandem: 20 feet 4 inches minimum
Rear Axle of Front Tandem to Front Axle of Triaxle and Rear Axle of Triaxle to Front Axle of Rear Tandem: 18 feet minimum
WEIGHT LIMITS
Gross Vehicle Weight: 137,700 pounds
Semitrailer Weight: The weight of the second semitrailer may not exceed the weight of the lead semitrailer.
Steering Axle: 600 lbs. per tire inch. Maximum weight 12,375 lbs.
Single Axle in Tandem: Maximum of 60% of tandem weight
Single Axle in Triaxle: Maximum of 40% of triaxle weight
Axle Group Limits:
Tandem Axle - 40,500 lbs.
Triaxle - 58,500 lbs.
7-AXLE TRACTOR-SEMITRAILER VEHICLE
AT 113,800 LBS. GVW
DIMENSION LIMITS
Overall Vehicle Length:
If the semitrailer is less than 48 feet long - maximum 69 feet
If the semitrailer is 48 feet or longer - maximum 74 feet
Vehicle Width: 8 feet 6 inches maximum
Vehicle Height: 13 feet 6 inches maximum
(load may extend an additional 6 inches)
Tandem Axle Spread: 4 feet minimum to 8 feet maximum between axle centers
Quad-axle Spread: More than 12 feet but less than 16 feet between centers of the extreme axles in the quad-axle group
Semitrailer Length Limits:
Overall Length Including Load - 53.15 feet (16.2 meters) maximum
Wheelbase (Kingpin to center of rearmost axle)* - 43 feet maximum
Kingpin Setback* - 3 feet 6 inches maximum
Rear Overhang (Center of 5th axle to rear of semitrailer)* - maximum of 35% of wheelbase length
Center of rearmost axle of tandem to center of rearmost axle of quad-axle**- 38 feet maximum
* Applies if semitrailer length exceeds 48 feet
** Applies if semitrailer length is 48 feet or less
WEIGHT LIMITS
Gross Vehicle Weight: 113,800 lbs.
Steering Axle: 600 lbs. per tire inch; maximum 12,375 lbs.
Tandem Axle limit: 40,500 lbs.
Single Axle in Tandem: Maximum of 60% of tandem weight
Semitrailer quad axle limit: 72,000 pounds
Single Axle in quadaxle: Maximum of 30% of quadaxle weight
C.M.R. 29, 250, Bureau of Motor Vehicles, ch. 170, app 250-170-A