MIL-T-62735 Trucks And Truck Tractors: Modified Commercial, General Specification ForThis specification covers general requirements for the classes, models and types of modified commercial trucks indicated in the specification title above and in 1.2 below. This specification is intended only as a document to be referenced in detail specification sheets that must, as a minimum, cover detailed truck body requirements and specify the model and class required from table I.

Pages 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - 26 - 27 - 28 - 29 - 30 - 31 - 32 - 33 - 34 - 35 - 36 - 37 - 38 - 39 - 40 - 41 - 42 - 43 - 44 - 45 - 46 - 47 - 48 - 49 - 50 - 51 - 52 - 53 - 54 - 55 - 56 - 57 - 58 - 59 - 60 - 61 - 62 - 63 - 64 - 65 - 66 - 67 - 68

MIL-T-62735

3.8 Crane. When specified for class 23 to 29 stake trucks (see 6.2), the vehicle shall have a frame mounted one man operated, fully hydraulic articulated boom type crane, between the cab and the stake body. The boom shall have an upper and lower section and a hydraulically operated extendable jib.

3.8.1 Crane capacity. The crane shall be capable of lifting a minimum load of 2720 kg

(6,000 pounds) when the load is located at a radius of 1520 mm (5 feet); and 1130 kg

(2,500 pounds) when the load is located at a radius of 3960 mm (13 feet), without causing the vehicle to become unstable. The vehicle shall be deemed unstable when anyone of the vehicle wheels lifts off the ground.

3.8.2 Range of crane movement. The jib shall be capable of extending not less than

840 mm (33 inches). The boom, when fully extended, shall have a normal lifting range of

7600 kg (25 feet) above ground level. The boom shall fold to a nestable travel height, between the truck body and the cab, not more than 2130 mm (84 inches) above the truck chassis frame.

3.8.3 Crane outriggers. The crane shall have double-acting hydraulic outriggers independently controlled and integrally mounted to the crane base. Each outrigger landing pad shall be not less than 900 cm2 (140 square inches) in area.

3.8.4 Crane check valves. The boom and outriggers shall have a check valve type locking system to prevent the load from dropping or the outriggers from retracting due to hydraulic or power failure.

3.8.5 Crane controls. Both sides of the vehicle shall have a full set of crane controls, and an outrigger control for the outrigger on that side of the vehicle. The crane and outrigger

controls shall be accessible from ground level. Controls shall be of the self-centering, fail-safe

type with hydraulic bypass overload valves. Crane controls shall have fine metering qualities for variable raising, lowering and rotating rates of motion of the crane boom.

3.8.6 Crane hydraulic system. The crane shall have a PTO driven hydraulic pump with PTO controls in the cab, identified in accordance with 3.10.5. The pump shall be of the positive displacement type. The pump shall provide a working pressure of not less than 12.4 Mpa

(1,800 psi). The crane hydraulic system shall contain the following minimum safety features:

(a) Check valve system in the boom and outrigger systems to prevent load drop due to hydraulic system failure.

(b) Flow valve in hydraulic lines or the cylinder to prevent boom damage due to sudden load-lowering stops.

(c) Cushioning valves in the boom rotating hydraulic system of rack- and-pinion mounted cranes to prevent damage due to sudden stops.