5-1. INTRODUCTION. MHE is large, mechanically powered equipment used to lift, transfer, and stack cargo. Proper use of MHE makes moving cargo through the terminal more efficient. The information in this chapter will give you a background on the different types of MHE.
5-2. FORKLIFT TRUCKS. Forklifts used in military break-bulk cargo operations range in capacity from 4,000 to 15,000 pounds. They have lift heights ranging from 144 to 210 inches. They are gasoline-, diesel-, or electric-powered vehicles. These lifts are operated on paved surfaces or rough terrain, depending on job requirements. Gas and electric forklifts are useful aboard vessels to handle itemized cargo. The three types of forklifts you will most likely encounter are gas-powered commercial forklifts, electric forklifts, and diesel-powered rough-terrain forklifts.
a. Types. The different types of forklifts are listed below.
(1) Commercial forklifts handle cargo on the pier, in the warehouse, and in the hold of a ship.
(2) Electric forklifts handle military explosives in the hold of a ship (Figure 5-1).
Figure 5-1. Electric forklift
(3) Rough-terrain forklifts (Figures 5-2, 5-3, and 5-4) move cargo off the road and over unimproved or soft surfaces, such as deep sand, mud, and snow. They have four-wheel power steering with independent controls for front and rear wheels. The steering operates all wheels in the conventional manner. Operators use a lever to select two-wheel steering, four-wheel crab steering, or four-wheel cramp steering. A rough-terrain forklift has a ground clearance of 14 inches and can climb slopes up to 45 degrees. The forks are power-operated. They tilt forward or backward to angles up to 45 degrees and to either side at angles up to 10 degrees from the horizontal. Operators may extend the loaded forks from the upright position a minimum of 21 inches above ground level.
(a) The 4,000 pound rough terrain forklift (Figure 5-2) is designed for use in close quarters for storage and shipping operations. In the air terminal area, it is used primarily for loading and unloading pallets and secondary cargo on vehicles. With the tines (forks) removed and addition of a front-mounted pintle hook, the 4,000 pound forklift makes an excellent pusher vehicle. It is capable of lifting and transporting loads up to 4,000 pounds. The tires will raise or lower and tilt forward or aft. Some models can even shift the load right or left. The only disadvantages of the 4,000 pound forklift are the limited weight lifting capability, short tines, and it cannot handle palletized 463L cargo.
(b) The 6,000-pound rough-terrain forklift (Figure 5-3) is mounted on low-pressure, high-flotation pneumatic tires. All four wheels drive and steer. One hydraulic system powers the steering mechanism and another system raises and lowers the lift. Special lifting arms are arranged so that the load can be raised or lowered in either a level or a pretilted position. For operations in landing craft, the forks are raised or lowered and tilted forward or backward more than those of conventional forklift trucks. When carrying a load, the driver normally has a clear view over the cargo. If he does not, he must move the vehicle in reverse, looking to the rear over his shoulder as he does when he operates a conventional model with a load that obstructs his view.
(c) Rough-terrain forklifts are used in beach operations and operated over nearly all types of terrain. They can also be used on the pier to handle large cases or a CONEX. A rough-terrain forklift is good for transferring cargo from and to landing craft at the shoreline and for moving cargo in open storage areas. It can operate in water to a maximum of 36 inches without using waterproofing kits, and to a maximum of 60 inches with kits installed.
(d) The 10,000-pound rough-terrain forklift (Figure 5-4) is built like the 6,000-pound forklift except that it is a larger vehicle. The primary difference between the two is that the 10,000-pound forklift is designed for operating in unimproved terrain. It has a lifting capacity of 10,000 pounds when the center of gravity of the load is within 24 inches of the mast.
Figure 5-4. Rough-terrain forklift, 10,000-pound
- Carry all loads tilted back slightly and just above the running surface.
- If the load blocks your view, drive the forklift in reverse.
- Never travel with a load tilted forward and never raise, lower, or tilt a load while the forklift is in motion.
- Always face the direction that you travel. This means looking over your shoulder if you must drive in reverse.
- Always back down ramps instead of going forward with the load in front of you.
- Never operate a forklift at a speed greater than five miles per hour.
- Always come to a full stop before changing directions. Avoid sudden stops.
- Do not allow passengers to ride on the forklift.
- Always use ground guides.
b. Safety. Operators should observe the following safety precautions:
a. Tractors. A warehouse tractor is a short, compact vehicle with a short turning radius. It is usually equipped with a sheet-steel bumper for pushing other equipment. Further, it has a towing hitch in the rear for towing a train of warehouse trailers and other equipment (Figure 5-5).
Figure 5-5. Warehouse tractor and trailers
b. Trailers. A warehouse trailer is a wheeled vehicle for transporting cargo over smooth surfaces. It is generally pulled by a tractor, but can be pushed as a four-wheeled hand truck.
c. Hand Trucks. Hand trucks are used for moving packages too heavy to be moved by hand (Figure 5-6). They are also used for increasing the unit load of small packages on occasional short trips.
(1) Some hand trucks have folding wings and curved braces between the legs so they can carry drums and barrels, as well as other types of packages. The wheels have solid or pneumatic rubber tires. The load capacity of the hand truck is 600 pounds and 95 cubic feet.
(2) An improvised extension on the blade or nose at the bottom of the truck will increase its cubic carrying capacity. The nose or blade is used to pry drums, barrels, and heavy boxes. These objects must be tipped back to rest against the truck's bed. When the truck is properly loaded, the wheels bear the weight, relieving the operator of strain. Operators will find that good loading is a matter of trial and error with the particular cargo to be moved. You should always assign two men to the task, with the truck normally in an upright position. When it is ready to move, the operator puts one foot on the bottom crosspiece to keep the handle toward him. He may be able to unload by himself, depending on the cargo.
5-4. PALLET JACKS. The pallet jack is a low-level hydraulic lift suitable for the horizontal movement of certain types of pallets (Figure 5-7). One person can operate this jack. Additionally, the jack is low enough to be passed through the opening in the bottom of a pallet. However, when the pallet is raised, the rear wheels must have clearance to reach the floor or deck. The general-purpose, four-way-entry pallet is designed so that it can be moved with a pallet jack. The pallet jack is not suitable for moving stevedore pallets.
a. Although pallet jacks are not an authorized TOE item, they may sometimes be justified, obtained, and used to move palletized cargo into final stowage position underdeck. Since pallet jacks cannot be used to tier cargo, it is necessary to stow one tier at a time. Personnel should lay dunnage between tiers so that the pallet jack can be maneuvered.
b. Operators pump the jack up by its handles. In pumping, the tines or forks are raised up on hinged rollers. They, with the wheels in front, support the jack as it is moved. There is a valve on top of the jack near the handle. Operators turn the valve to the right when raising the jack and to the left when lowering it. The projections bracketing the front wheels are brake pedals.
5-5. CRANES. Cranes use a projecting swinging arm to lift, swing, and lower loads which cannot be reached by other equipment or are too bulky or too heavy to be moved otherwise. Since their chief advantage is their reach, they should never be used to carry a load from one place to another except for short distances. The four types of cranes discussed here are rough-terrain cranes, floating cranes, gantry cranes, and truck-mounted cranes.
a. Types of Cranes. There are four types of cranes. Each is listed below.
(1) Rough-terrain cranes are wheel-mounted, diesel-driven cranes designed for operating in rough terrain. One rough-terrain crane, with a 20-ton capacity and a 30-foot boom, is equipped with an earth moving blade for improving beach working area or making its own path in unimproved terrain (Figure 5-8). A RTCC has an all welded steel frame and four-wheel drive. The rear-mounted engine has a six-speed (forward and reverse) transmission. Hydraulic, double box, sliding beam outriggers are integral with the carrier frame (Figure 5-9).
(2) Floating cranes are mounted on barges. They vary in lifting capacity. Some commercial cranes have capacities up to 240 long tons. The two standard floating cranes found in the military inventory have capacities of 60 and 89 long tons (Figure 5-10). Their auxiliary hoist can lift 15 long tons at a radius of 122 feet, 6inches. The barge has an overall length of 140 feet and a beam of 70 feet. Floating cranes work the offshore side of a vessel. Cargo handlers discharge heavy lifts to the deck of the cranes or to the barge tied alongside. Both cranes may reach cross the ship and discharge the lift, either on the pier or to clearance carrier equipment.
(3) Gantry cranes range in capacity from 3 to 45 tons. The legs of the cranes are supported on wheels that run on tracks on the pier apron. Operators use gantry cranes for loading and discharging barges, railcars, and trucks; for handling heavy lifts aboard vessels; and for handling general cargo in place of the ship's gear (Figure 5-11).
(4) A truck-mounted crane is a commercially designed vehicle with a hydraulically operated boom assembly mounted on a carrier chassis. It has tandem axles, front and rear, dual rear tires, and a 224-inch wheelbase. Truck-mounted cranes vary in lifting capacity. Some commercial cranes have capacities up to 240 long tons. The two types of truck-mounted cranes found in the military inventory are the 140- and 300-ton cranes.
(a) The truck-mounted crane, 140-ton is designed to lift, handle, and place loads of up to 140 tons. The truck carrier uses 8 x 4 drive. All control and instruments necessary to drive the carrier are inside the cab. A Detroit Diesel 6V92TC series engine powers the carrier. A Detroit Diesel 6-71 series engine powers the upper machinery. All controls and instruments necessary to operate the upper machinery are located in the operator's cab. The upper machinery has a tubular boom and a lower and upper boom assembly section with hook block (Figure 5-12).
- Always check the crane and all slings, cables, chains, and hooks before starting an operation to avoid possible damage to the machine or injury to personnel.
- Keep the crane level once motion is started.
- Never swing a crane rapidly because centrifugal force can get the mechanism out of control or even upset the crane.
- Use standard signals and ground guides for all operations.
- Keep the boom at least 10 feet away from power lines.
- Do not lift weights greater than the rated capacity of the crane for the boom radius you must use.
- Put all controls in neutral before servicing a crane or making repairs or adjustments, including troubleshooting.
(b) The truck-mounted crane, 300-ton, is designed to lift, handle, and place loads of up to 240 tons. All controls and instruments necessary to drive the carrier are inside the cab. All controls and instruments necessary to operate the upper machinery are inside operator's cab. The upper machinery has a tubular boom and a lower and upper boom assembly section with hook block that extends up to 130 feet (Figure 5-13). The 300-ton crane can work offshore on barges or improved beach areas.
b. Instructions for Safe Crane Operations. Operators must understand a crane's lifting capacity in order to use one safely and efficiently. While operators cannot increase capacity beyond the limit set by the manufacturer, they must take into account changes in capacity. These changes are caused by changes in the length or angle of the boom and in the resulting boom radius. Boom angles are measured in degrees, starting at zero, with the boom parallel to the ground. Boom radius is the horizontal distance between the center of rotation (the center of the turntable or the center pin) and vertical line through the center of the hook. Signals for crane operations are shown in Chapter 3. Operators should take the following safety precautions when using cranes:
5-6. HELICOPTER POSITIONING DOLLY. The helicopter-positioning dolly moves skid- or wheel-mounted helicopters, (UH-1, AH-1, and UH-60A) laterally or sideways to their designated stowage positions aboard ship. They are especially useful aboard RO/RO ships. These dollies make a tight stow possible when loading helicopters.
a. The helicopter-positioning dolly (Figure 5-14) is made up of two 4-ton capacity hydraulic service jacks (same type used in most garages). They are positioned side by side and spaced 35 inches apart. A 4-inch I-beam, approximately 5 feet long, is welded across the lifting pads of the two jacks. A 4-inch wide strip of steel plate is welded, full length, to both sides of the I-beam to form a box beam with a vertical partition down the middle. The two cavities receive and hold a snug-fitting, tempered steel bar, machined to fit. The bars slide in and out of the beam, one to the left and one to the right. This extends the width or "reach" of the beam to conform to the width (distance between) of the skids or wheels of the helicopter. A triangular piece of steel plate, shaped like a coat hanger, is secured to the ends of the sliding at right angles and secured in place.
CAUTION: Take care to prevent or restrain the free rolling movement of helicopters on inclined decks. Failure to do this could result in damage to helicopters.
- Remove the entire dolly assembly from the box.
- Cut the metal banding and remove the dust covers (refer to Figure 5-14).
- Insert the sliding bars in the box beam housing (both sides).
- Use a 7/16-inch box-end wrench to remove the hinge pin bolts.
- Pull out right and left hinge pins.
- Rotate and fit the right yoke into the segment and jack frame while holding the release knot. Make sure the cam is on the right side of the release disk.
- Push the hinge pins into the yoke.
- Tighten the hinge pin bolts.
- Secure the opposite handle using the same steps.
- Install the dust covers after both handles are secured.
(1) Assembling the helicopter-positioning dolly. There are four of these dollies stored aboard each of the FSS vessels. When not in use they are taken apart, boxed, and stored with the rest of the ship's cargo-handling gear. To reassemble and make them operational-
(2) Moving skid-mounted helicopters. With the sliding bars fully retracted, the dolly is centered under the tail of the helicopter, then it is rolled forward and maneuvered past any items sticking out from the belly of the helicopter (drain tubes, bayonet antennas, and so forth) and past the new landing gear cross tub. When the shackles in the triangular end plates are a beam of the lifting lugs on the skid mounts, the jacks are raised up and the sliding bars are extended to just above the existing lifting lugs in the top of each skid tube and the shackles are attached (see Figure 5-15). With one person at each jack handle, the helicopter can now be lifted. Lift the helicopter until the skids are 1 to 2 inches off the deck.
NOTE: Although the helicopter can be lifted to more than 12 inches off the deck, it is foolhardy to lift the helicopter any higher than necessary to clear obstacles on the deck, such as seams on tie-down fitting.
Figure 5-15. Skid-mounted helicopter
(3) Moving wheel-mounted helicopters. When using the dolly to move a wheel-mounted helicopter such as the UH-60A, the dolly is rolled under the helicopter, then the lift is made by aligning the jack point mating holes in the blocks welded to the triangular and plates on the sliding bars (see Figure 5-16). Then you lift the helicopter up until the wheels clear the deck 1 to 2 inches.
b. Depending on the weight and size of the helicopter, four to eight cargo handlers may be required to move a helicopter in any given direction by pushing against the dolly on the landing gear or on the strong points of the helicopter. Occasionally, more persons may be required to change the direction of roll or to overcome some obstacle on the deck of the vessel. The tail wheel of the helicopter is turned in the direction of movement with its standard steering tow bar.
5-7. CONTAINER HANDLERS. The RTCH (Figure 5-17) is used for loading, unloading, handling, and stacking containers weighing 50,000 pounds (22,700 kg) or less. It operates over rough terrain including beaches, snow, mud, and cross-country. The RTCH fords up to 60 inches (152 cm) of salt water and makes over the shore landings. The RTCH comes with a 20-, 35-, and 40-foot top handler. It also comes with forks. It may be used to load and unload flatbed trailers and railcars.
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