M870A1 40-ton Low Bed Semitrailer
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M870A1 Semitrailer, Lowbed: 40-ton Construction Equipment Transporter

Semitrailer, Lowbed: 40-ton Construction Equipment Transporter M870A1
Semitrailer, Lowbed: 40-ton Construction Equipment Transporter M870A1.

The M870A1 semitrailer is an improved version of the M870 semitrailer with the same mission of transporting construction equipment and material. It is towed by prime movers such as the Marine Corps MK48/16 LVS Semitrailer Adapter configuration. The semitrailer can transport a payload of 40 tons cross-country at 20 mph and on highways at 40 mph.

The gooseneck of the M870A1 semitrailer drops down to form a ramp for loading and unloading of equipment. To widen the bed and to help stabilize and support the load, twenty-four permanent outriggers are stored in an open stowage compartment on the gooseneck behind the air and electrical connectors. A spare tire is mounted on the rear deck of the vehicle. The prime mover supplies brake air pressure and control of the brakes.

The M870A1 has five D-rings on each side. It also has two D-rings and two 17-ton shackles on the cargo bed and two D-rings and two 17-ton shackles on the gooseneck.

M870A1 Changes from the M870 Semitrailer

The design of the M870A1 was changed so that the M870A1 cannot be loaded or unloaded from the rear as can the M870. In addition, the M870A1 semitrailer has different dimensions than the M870 and changed from the M870 in the following items:

Item M870 M870A1
Chock Block Two supplied None supplied
Blackout Lights No Yes, two 24V
Other Lights Differences in clearance lights, reflectors, rear stop/turn lights
Wheel Type Disk, ten studs Spoke, six studs
Rim Type Advance military Tube
Rim Spacer None Goodyear K type
Bridge Classification 60 tons 54.5 tons

Information in this table from TM-5-2330-378-14&P.

M870A1 Semitrailer Characteristics

Length 42 ft 6 in (13.0m)
Width 8 ft 0 in (2.4m)
Height 6 ft 0.875 in (1.9m)
Ground clearance (40-ton load) 1 ft 5.625 in (0.4m)
Curb weight 9.5 tons (8618kg)
Max payload; 40 tons (36,287kg)
Gross weight 49.5 tons (44,905kg)
Tires 13 tires 10:00x15 14-ply, commercial highway tread
Brakes S-cam, two-shoe, double anchor, interval expanding, air actuated
Suspension Triaxle mechanical
Max speed empty 55 mph (89kmh)
Max speed 40-ton load 40 mph (64kmh)

Table data from TM 5-2330-378-14&P

The full nomenclature for this trailer is Semitrailer, Lowbed: 40-ton Construction Equipment Transporter M870A1. The M870A1 was assigned NSN 2330-01-224-9245.

The Operator's and maintenance manuals for the M870A1 include:

  • TM 5-2330-378-14&P OPERATORíS, MAINTENANCE & PARTS MANUAL (M870/M870A1)

The M870 was manufactured by Shoals American Industries, Inc.