463L PALLETS AND SHORING
18-1. INTRODUCTION. The Air Force devised a cargo handling system, called the 463L System that reduces aircraft ground time, loads aircraft more fully, and eases the ground handling of cargo. One of the key items is the master pallet (463L pallet), which then turned sideways fits on the rollers of the C-130 and C-141 aircraft, and when turned lengthwise, fits on the bed of a truck. Combining the 463L vehicles, pallets, rollers, and rails within the aircraft, can reduce ground time by as much as 75 percent. This chapter also discusses types of shoring and how, when, and where it will be used in loading cargo aboard aircraft.
18-2. CONSTRUCTION OF 463L PALLETS. The 463L pallet dimensions are 108 inches by 88 inches by 2 1/4 inches. It weighs 337 pounds and has a total load capacity of 10,000 pounds. The desired load capacity is 7,500 pounds. The pallet has a balsa wood core, and is covered with corrosion-resistant aluminum. It is framed on all sides by aluminum rails which have 22 tie-down rings attached with six rings on each of the long sides and five rings on each of the short sides. The rails also have indents (notches) which can accept rail locks when the pallet is put on an aircraft (Figure 18-1). The C-130 and C-141 aircraft are fitted with a dual-rail system. The rails are fitted with detents (rail locks) to lock the pallet in place. These detents prevent forward and aft movement of the pallets while the aircraft is in flight. The usable dimensions of the 463L pallet are 104 inches by 84 inches. Four inches around the pallet are used to secure the straps, nets, or chains.
Figure 18-1. View of rails and indent on 463L pallet
a. Use blocking under the pallet. Lay three blocks the length of the pallet.
b. Use dunnage between the pallet and cargo with sharp edges.
c. Palletize cargo from the heaviest to the lightest items. The lighter and smaller items should be placed on the top or along the sides of the heavier cargo.
d. Place containers marked "This Side Up" upright, and labeled cargo with their labels faced out.
e. Distribute large and heavy items evenly from the center out (Figure 18-2) to prevent the pallet from being heavy ended.
Figure 18-2. Weight distribution
f. Build the load in a square or pyramid shape (Figure 18-3) to make the load stable and easier to handle. It is then easier to secure the cargo to the pallet.
Figure 18-3. Shape of loads
g. Use a pallet template or measuring stick to ensure that the height restrictions are not exceeded. The maximum height allowed is 96 inches except for 76 inches used in restricted areas.
h. Use care when loading cargo using MHE, especially when using forklifts with bare tines.
i. Use at least two attaching points when winching (pulling) a pallet.
NOTE: Never push or slide a pallet across concrete floors or ramp surfaces. This will damage the bottom skin of the pallet.
a. Cargo Nets. Three nets make up a set. Two side nets are attached to the rings on the pallets and go around the sides of the load, and a top net goes over the top of the cargo.
(1) The top net is attached to the side nets by hooks and rings. The nets have many adjustment points and can be made to fit any load.
(2) A set of large 463L pallet nets has a maximum capacity of 10,000 pounds at 8 Gs when properly installed.
NOTE: When more than 5,500 pounds of cargo are loaded on a pallet, use two sets of side nets.
b. Procedure for Netting Pallets. Personnel should follow these steps for netting pallets:
NOTE: Before netting the cargo to the pallet, cover the pallet with plastic pallet covers.
Step 1. Lay the nets on the floor, untangle them, and inspect for missing attachments (hooks and straps).
Step 2. Start with the left ring side of the numbers 26 through 30 (see Figure 18-4). Attach hook 1 on the side of the net to ring 1 on the pallet.
Figure 18-4. Side netting procedures
Step 3. Continue hooking up the side net (numbers 2 through 11).
NOTE: Always start on the long side of the pallet and work from left to right.
Step 4. Attach the other side net on the other two sides of the pallet (follow same procedure as steps 2 and 3).
Step 5. After both side nets are attached, lift strap 31 of both nets over the corner of the cargo on the pallet. This strap is adjustable at point 32.
Step 6. Attach adjustable hook 21 to ring 26 of the opposite net. Lift straps just attached over the corner of the cargo in the same manner as in step 5.
Step 7. Continue hooking ring 22 to ring 27, ring 23 to ring 28, ring 24 to ring 29, and ring 25 to ring 30. Work from the top down.
Step 8. After the side nets are attached and adjusted, place the top net over the pallet. The sides of the net with five straps (A through E) are placed on the long side of the pallet.
Step 9. Attach A to 12, B to 13, C to 14, D to 15, E to 16, F to 17, G to 18, H to 19, and I to 20.
Step 10. Finish attaching the rest of the top net to the other side net in the same manner as in step 9 (Figure 18-5).
Figure 18-5. Top netting procedures
Step 11. Tighten all the nets.
Step 12. Attach the 4 J hooks to the 4 K rings. These straps go around the corner of the cargo on the pallet.
Step 13. Secure the ends of the straps; tuck them in to ensure that they will not get caught in the rail system when loading the pallet aboard the aircraft (Figure 18-6).
Figure 18-6. Typical net attachment
Step 14. Attach the pallet documentation to the net.
18-5. MULTI-PALLETIZATION. When shipping cargo that exceeds the dimensions of the 463L pallet, two or more pallets may be joined together. This is referred to as marrying the pallets. When two pallets are married, they are referred to as a double pallet or a two-pallet train. The same applies to three, four, or five pallets married together.
a. Inspect the Pallet. Before pallets can be married, personnel must inspect them on the top, bottom, and sides to ensure that they are in good condition. The tops and bottoms should be clean and in good repair. The side rails should not be bowed, and the tie-down rings should be securely mounted.
b. Marry the Pallets. After the pallets have been inspected and accepted, they can be married. Place the pallets on the cargo loading dock (Figure 18-7) so that the intents and detents on the long side of the pallets are aligned.
Figure 18-7. Loading dock
(1) Placement of spacers. Once the pallets are aligned, put spacers between the pallets (Figure 18-8) between the two ends in the indents and detents. Use at least two spacers between the pallets being married; use more if necessary. The spacers keep the pallets in line and properly spaced so that they will lock into the rail system of the aircraft (Figure 18-9).
NOTE: Spacers are locally manufactured out of two pieces of 3/4-inch plywood.
Figure 18-8. Use of spacers
Figure 18-9. Sampler spacer
(2) Securing the pallets together. Use tie-down devices to chain pallets together. Figure 18-10 shows two methods of marrying pallets. These devices are available in the unit.
c. Loading Cargo on Married Pallets. Long heavy cargo is loaded first and distributed over the pallets to prevent them from becoming heavy ended. Light cargo is stacked on top and along the sides of the heavy cargo. If cargo is labeled, make certain that the labels face out and are visible. Figure 18-11 shows the proper use of pallet barriers.
(1) Weight distribution. Distribute the weight evenly over all the pallets. Never exceed the dimensions and weight limits for the designated aircraft.
Figure 18-10. Methods of marrying pallets
Figure 18-11. Pallet barrier
(2) Accountability. Tally each item as it is loaded on the pallet. Make sure that the tally sheets indicate that the pallet is married. Attach one copy of the tally sheet to the cargo.
d. Tie-Down Techniques. Some of the key techniques of tying down large items are as follows:
(1) Use a front barrier or buffer board and a chain gate for loose heavy cargo, such as helicopter blades or tent poles.
(2) Use chain and devices for large items such as canned engines and wheeled equipment. Never put more than 50 percent of the tie-downs on axles of wheeled equipment.
(3) Use 463L nets for loose or light items such as small boxes.
(4) Always use a chain gate (Figure 18-12) for heavy items such as large cases or reels.
Figure 18-12. Chain gate
18-6. STORAGE OF 463L PALLETS AND NETS. With reasonable care and protection, the 463L pallet and their cargo nets should last indefinitely. Good supervision ensures that adequate care is taken in handling and storing pallets and nets.
a. Storage of pallets. Personnel should follow these steps:
(1) Clean each pallet before it is stored.
(2) Inspect the top and bottom of each pallet.
NOTE: Pallets with dents, gouges, or scratches that do not fracture the skin can be kept and stored. If the pallet has bent rails, missing tie-down rings, or holes, or if the metal skin is peeling, turn it in for repair.
(3) Stack pallets topside up. If pallets are stacked upside down, the tie-down rings will be damaged and the skin will be torn.
(4) Stack pallets 40 feet high, with three pieces of dunnage between each group of 10 pallets.
b. Storage of cargo nets. Personnel should follow these steps:
(1) Lay out each set of nets and inspect for breaks in the webbing or straps, tears where the webbing is sewn, or missing rings, hooks, or attachments.
NOTE: If you reject one of the nets for damage, send the complete set in for maintenance and repair.
(2) Clean and dry the nets before they are stored.
(3) Lay out the two side nets and the top net. Fold them, and then secure the three nets together.
(4) Stack and store the nets in sets in a dry and well-ventilated storage area.
a. General. The HICHS is a cargo-handling system that provides low friction load/unload conveyor ramps. It also includes conveyors for moving cargo within the aircraft. Figure 18-13 shows the HICHS installed in a CH-47 helicopter. The total weight of the HICHS is 825 pounds. The HICHS consists of three sections (see Figure 18-14).
Figure 18-13. HICHS installed in a CH-47 helicopter
(1) Cabin/cargo area. This section is made up of three outboard rail/roller assemblies on each side of the cabin. The assemblies use twenty-six 5K tie-down fitting assemblies, eight 10K fitting assemblies, and two tie-down fitting assemblies. Four inboard guide/roller assemblies are mounted along the centerline of the cabin floor. They are secured with 10 centerline ring plug assemblies to the 5K rings in the floor.
(2) Ramp section. The ramp section of the system includes a right-hand ramp guide rail-roller assembly and a right-hand ramp inboard guide/roller assembly. There are also left-hand assemblies. A separate ramp support (see Figure 18-14) is used during loading and unloading operations.
Figure 18-14. Three sections of the CH-47 HICHS
(3) Ramp extension section. There are two ramp extension roller assemblies and two ramp extension support assemblies.
b. Loading Operations. The loading methods for the CH-47 HICHS are as follows:
(1) 463L pallets. Up to three pallets may be winched or manually loaded on the HICHS. Figure 18-13 shows the loading of 463L palletized cargo.
(2) Warehouse pallets. These are the standard 40- x 48-inch pallet. When they are loaded, the 40-inch side of the pallet should be positioned across the handling system so that the 48-inch side is on the ramp guide rail. Eight to ten warehouse pallets can be loaded aboard the helicopter. During the loading, the pallet should be forklifted onto the ramp extension and balanced onto the outboard roller. Pallets may be winched or manually pushed into place. On the ramp, the pallet should be pushed outboard.
(3) Weight restrictions. Individual pallets may weigh up to 3,700 pounds. Pallets weighing 2,150 pounds or less may be loaded without any problem. However, in order to maintain floor isolation, the sum of the weights of longitudinally adjacent pallets must not exceed 4,300 pounds.
(a) A mix of pallets weighing, for example, 3,000 and 1,200 pounds, requires alternate loading.
(b) If the load consists of only pallets, each weighing more than 2,150 pounds, the pallets MUST be spaced longitudinally. To determine the distance required for spacing, use this formula: Weight in pounds divided by 45.2 equals distance in inches from center of one pallet to the center of the adjacent pallet. To determine spacing required for a load of pallets weighing 3,000 pounds each, perform this computation: 3,000 divided by 45.2 equals 66 inches center to center.
(c) Pallets spaced longitudinally require tie-downs for longitudinal, lateral, and vertical forces. There is no requirement to use a barrier system.
(4) Wheeled vehicles. These can be either winched in or manually loaded. For vehicle loading and specific tie-down procedures, refer to FM 55-450-2.
(5) Personnel. The HICHS can carry personnel only, or both cargo and personnel. If both are loaded, cargo handlers should load the cargo forward of the personnel.
18-8. SHORING. Shoring consists of wooden planks or similar materials placed on the cargo floor or deck of the aircraft. Five basic types of shoring are used when loading aircraft: approach, rolling, parking, bridge, and sleeper shoring. Illustrations of these shoring types are contained in FM 55-9. Two major purposes for using shoring aboard aircraft follows.
a. Protection of the Aircraft Floor. All tracked vehicles with metal cleats and studs, and vehicles with steel wheels require a minimum of 3/4-inch shoring. Shoring is required also for cargo in drums, trailer tongues, or any other object that could puncture or dent the aircraft floor. Shoring prevents metal-to-metal contact eliminating sparking caused by the skidding of cargo.
NOTE: The user is responsible for furnishing all types of dunnage that may be required.
b. Distribution of Weight. Properly laid shoring will distribute weight evenly over a large area. The psi of cargo placed on the aircraft floor may be above the specified floor limits. Distributing this weight evenly and over a greater area allows a load of higher-than-normal weight concentration to be carried.
(1) The weight of the load resting on shoring is not spread equally over the entire area of contact between the shoring and the surface. To increase the area over which a load is distributed, extend a plane drawn downward and outward from the peripheral line of contact of the load at a 45-degree angle, until it intersects the surface on which the shoring rests (Figure 18-15). Shoring increases the area of contact approximately equal to the shoring thickness on all sides of the object. A 2-inch thickness of shoring increases the area of contact by approximately 2 inches on all sides of the item resting on it. This spreading effect of weight by simple shoring is the same regardless of the shape of the area of contact.
Figure 18-15. Increasing an area by shoring
(2) Formulas are used to compute the psi imposed on the floor of the aircraft by objects of different shapes.
NOTE: Carry answers only to the tenth place. Always increase psi answers to the next higher tenth if there is any remainder. Never increase area answers to the next higher tenth regardless of the remainder.
(a) Rectangle. The weight of the object, divided by the length times the width, equals psi.
(b) Triangle. The weight divided by one-half the base of the triangle, times the height.
(c) Circle. The weight, divided by the diameter squared, times .785.
(d) Circular barrel with rim. The weight, divided by the outside diameter plus the inside diameter, times the difference, times .785.
(e) Tire pad. Weight of the axle divided by length, times width of tire pad, times .785, times the number of tires on the axle. (Each axle of a vehicle must be computed separately.)
(3) Determining the area of contact using shoring.
(a) The area of contact will be increased by the thickness of the shoring laid.
NOTE: Shoring is only effective up to 2 inches in thickness.
(b) If shoring 2 inches thick is laid under an object that has a base of 50 inches by 40 inches and weighs 4,000 pounds, add 2 inches to the dimensions in each direction of the base.
50 inches + 2 inches x 40 inches + 2 inches = 52 x 42 = 2,184 square inches of contact
Use of shoring to increase the area of contact will decrease the psi. Shoring can make the difference between carrying and not carrying a given piece of equipment or load.
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