Military Pallets, Boxes and Containers – Part 6 Aircraft Pallets and Containers

5,539

Pallets and containers in the previous posts exist mainly on the surface, sea or land. In the air, ISO containers represent a 4 tonne weight overhead and conventional pallets cause all sorts of problems because it is rather difficult to get a fork lift truck through the skin of an aircraft!.

So for air transport, where different constraints and rules apply, pallets and containers have developed on their own path, pretty much unconnected with intermodal container and the familiar wood NATO/Euro pallet.

Moving stores with aircraft is expensive, of course, but where speed is needed or alternative means are hazardous or compromised in some way, there is no other option.

And so, specialist devices and techniques are used.

The two main systems in use are the 463L pallet and Unit Load Device or ULD.

The first is military and the second, civilian. Of course, there are always crossovers and grey areas but in general, the 463L pallet system is mostly used in a military context. Unlike the pallets and containers in the previous parts of the series, where military and civilian systems have converged, in the air transport world, the two are still very much apart.

To provide some scale for the number of pallet movements this parliamentary question does provide some useful context. It was tabled by Angus Robertson of the SNP, enquiring about moving supplies to Afghanistan by air and the difference between the RAF and chartered civilian aircraft.

Angus Robertson (Moray, Scottish National Party)

To ask the Secretary of State for Defence what estimate he has made of the (a) number of pallets, (b) tonnage of supplies and (c) number of flights to Afghanistan taken by (i) RAF transport and (ii) leased transport aircraft in each of the last six years.

Peter Luff (Parliamentary Under Secretary of State (Defence Equipment, Support and Technology), Defence; Mid Worcestershire, Conservative)

The Ministry of Defence (MOD) does not lease aircraft, ie rent them to be flown by MOD pilots, but rather charters with private companies to fly on the MOD’s behalf. The number of pallets, weight of supplies (in tonnes) and number of flights taken by RAF and civilian chartered aircraft to Afghanistan over the last six calendar years are as follows:

RAF Aircraft Civilian Leased Aircraft
Number of pallets Weight of supplies (in tonnes) Number of flights Number of pallets Weight of supplies (in tonnes) Number of flights
2005 890 2579 144 0 0 0
2006 2368 6572 394 1652 3792 116
2007 3268 7550 513 3258 8678 234
2008 3072 6709 538 4113 8817 266
2009 3654 8225 619 4756 10675 461
2010 2792 6971 533 3756 9568 443

Digging those figures a little more deeply

  • In the 5 years shown, the RAF averaged just under 14 tonnes and 6 pallets per flight with civilian charters, 30 and 13 respectively.
  • The split between the RAF and civilian charters was roughly 50:50
  • Both the number of pallets per flight and tonnes per flight have on average declined year on year for both

It is very difficult to draw any meaningful conclusions, the RAF has a more people focussed mission as only aircraft fitted with DAS can carry personnel, outsize cargo might not weigh much and not be palletised or the RAF is concentrating on tactical delivery in a hub and spoke arrangement in theatre.

Despite this, the pallet count is interesting in the scope of this series of posts, although the answer did not specify what a ‘pallet’ actually was!

The 463L Materials Handling Support System

The 463L is a military load carriage system that comprises pallets, netting, bags and material handling equipment specifically for the carriage of stores on tactical transport aircraft.  It came into service with the United States Air Force (USAF) in April 1963.

463L Pallet

The 463L pallet (also known as the HCU-6/E) is the main component of the 463L Materials Handling Support System.

The pallet and handling systems are designed with rolling in mind, a Euro pallet is lifted and shifted, a 463L is rolled. Constructed balsa wood with an aluminium skin the 463L is 88″ by 108″ and 2.25″ thick, inches not metres. An empty pallet weighs 290 lbs (131kg) or 355 lbs (161kg) with the net fitted which also needs a couple of inches space around the pallet edges to secure.

Each pallet can carry up to 10,000 lbs or about 4.5 tonnes.

463L HCU6 Pallet
463L HCU6 Pallet

Using the 463L system can reduce loading and unloading times by in excess of 75%, it was a significant improvement on previous methods.

Both top and bottom surfaces of the pallet are smooth in order to facilitate rolling and loading.

Cargo nets and slings are used to secure the material to the pallet.

To carry loads that exceed the dimensions of a single pallet multiple pallets can be ‘married’ together using spacers.

Modern 463L pallets no longer use the balsa wood core and instead use a series of aluminium extrusions bonded together but they still use a smooth aluminium sheets to form the top and bottom surfaces, the result is longer life and increased rigidity.

In February 2014, the MoD let an £8.3 million 4 year contract to AAR for the supply of 463L 4.5 tonne capacity Air Cargo Pallets, like I said, they are not cheap, about £2,000 each. The MoD has also used 463L pallets from Airborne Systems

The A400M can carry 9 463L pallets, 7 on the main cargo deck and two on the ramp, all whilst keeping 54 seats available for personnel. Recognising the problems with the C130J cargo area winch and Dash 4a Cargo Handling System the RAF, and others, formed the Cargo and Aerial Delivery Working Group (CADWG) to make sure that expert advice was incorporated into the design from the very start. This approach has reportedly been very successful with a number of critical design issues corrected before production, the floor tie down grid for example. Other reports are less complementary about the A400M cargo floor, especially in comparison with the C17, which is apparently the gold standard. Hopefully, the A400M will provide a big improvement over current aircraft. As regular TD readers will know, I am very enthusiastic about the A400M but recognise any new system will always have teething troubles to be resolved.

Although not all of the UK’s A400M’s will be fitted with the 5 tonne crane to enable off loading at locations without suitable air cargo handling equipment all of them will have a reinforced floor (just over 9 tonnes per linear meter) to enable carriage of heavy vehicles, specifically the Terrier armoured engineering vehicle.

The floor system will also have pop up rails and electrically operated pallet locks.

A400M Cargo Hold
A400M Cargo Hold

The nets used with 463L pallets might look slightly overkill but they are rated at 9G and have to ensure loads are secured at a range of aircraft attitudes, the consequences of load shift during flight can be catastrophic.

Aircraft like the A400M and C17 are actually volumetrically inefficient when it comes to pallet carriage, look at any image of a C17, Hercules or similar military aircraft carrying pallets and you will see a massive amount of free space, fresh air, or indeed, wasted space.

As can be seen from the images above, the 463L can be ‘floor stacked’ or loaded with other conventional pallets and containers. Putting a pallet on top of another pallet might not seem particularly efficient but it does work.

090109-N-1120L-075

Quadcon Container on 463L Pallet
Quadcon Container on 463L Pallet
QUADCON Container secured to a 463L Pallet
QUADCON Container secured to a 463L Pallet

3D Flight Cases

463L pallet and Peli Cases 2

A number of manufacturers have also created lightweight shelters, the VRR Mobility Shelter and AAR ISU for example.

The Red Arrows groundcrew depart Aalborg on a C17 after an overnight stop en route back to Scampton following a successful series of displays in Moscow as part of the celebrations of the 100th Anniversary of the Russian Air Force. In the centre is an ISU used for carrying spares and tools provided by AAR Mobility Solutions
The Red Arrows groundcrew depart Aalborg on a C17 after an overnight stop en route back to Scampton following a successful series of displays in Moscow as part of the celebrations of the 100th Anniversary of the Russian Air Force. In the centre is an ISU used for carrying spares and tools provided by AAR Mobility Solutions

Mobility Container 1

ABB-container(3)

ABB-container(5)

VRR also make a VIP comfort shelter based on the 463L footprint

There are also a number of specialist containers based on the 463L dimensions, everything from dog kennels to all terrain vehicle containers.

It must also be noted that the 463L pallet is not used beyond the aircraft domain, it is not an intermodal system. 463L pallets are not transferred from aircraft to trucks because mechanical handling equipment used in the land domain, ISO containers and vehicle load beds are fundamentally ill suited to the 463L.

There are also a handful of specialist non standard 463L ‘style’ containers including the HCU-12/E, a half size 463L and specialist helicopter pallet designed for entry through side doors.

I also like this neat solution from FLS;

Although technically they can be used beyond the airhead or Air Port of Disembarkation (APOD) they rarely are due to cost and convenience, in service land mechanical handling equipment like the JCB Telehandlers cannot lift 463L pallets because roller fork attachments are not issued as standard.

This brings me on to the subject of pallet handling for 463L’s.

463L Pallet Handling and Storage

The 463L is designed for ease of handling but only with the correct equipment.

For locations with no mechanical handling equipment many aircraft are fitted with integral cranes and winches that can be used to manipulate pallets but this is slow. Lifting equipment like cranes and hydraulic jibs can also be used although again, this is slow and inefficient.

Other than this there are two equipment types, roller forklift extensions and specialist loaders.

Forklift Roller Tine Extensions

This simple device slides over a a fork lift which provides a powered or unpowered roller bearing onto which pallets can be moved

Forklift rollers
Forklift rollers
463L Pallet with Roller Forklift
463L Pallet with Roller Forklift

They are lifted from their racks or staging and moved to the aircraft. After lining up with the aircraft cargo bed the pallet is slid off the rollers and on pushed onto the aircraft.

463L Pallet lift

 

A forklift truck loads a pallet of humanitarian aid to Pakistan onboard a C-17 aircraft, following devastating floods in the country in 2010.
A forklift truck loads a pallet of humanitarian aid to Pakistan onboard a C-17 aircraft, following devastating floods in the country in 2010.

463L Pallet lining up

RAF Delivers Aid to Flood Hit Pakistan

Using a set of these the in service JCB Telehandler 4,000kg could quite easily place a 463L pallet onto or off the cargo deck of an A400, c130 or C17 although it might struggle at maximum outreach. The RAF purchased 27 Telehandler 525-50’s in 2002.

Also in service is the 7.2 tonne lift Dan Truck 9680D Counterbalance Fork Lift Truck, 22 of.

RAF Finnings Dan 9680MD Counterbalance Fork Lift truck
RAF Finnings Dan 9680MD Counterbalance Fork Lift truck

A few videos to illustrate the loading and  unloading process using fork lift trucks

As can be seen from the videos, forklift rollers are not absolutely necessary for handling 463L pallets but they make it much easier.

The forklift tines fit between the rollers on the aircrafts ramp.

This method means that ramp loading capacity needs to be taken into consideration because not all cargo aircraft ramps can take the same loads as the main cargo deck (C130 ramp limit is about 2 tonnes), although supports can be used in some cases to alleviate this problem, like axle stands.

Because the pallets are on rollers the objective is to ensure that the aircraft and pallet remain aligned and flat.

The Dyneema Lightweight Pallet Net saves weight, and fuel.

Specialist Loaders

For higher speed loading  and unloading there are specialist items of equipment available that can deal with multiple pallets, vehicles and outsize items in addition to 463L or civilian pallets and containers.

They are available from a small number of manufacturers including TLD, JBT Aerotech and our very own AMSS from Wales, who make the Atlas K loader, in service with the RAF.

The Atlas K Loader for example can lift up to 20 tonnes and they can operate inline if more than one is available. The only problem with these very useful devices is they need a firm, flat and stable surface. They are also designed to be air portable, weighing in at about 11 tonnes.

The RAF purchased two new Atlas K loaders a few years ago and modified the existing ones for use in Afghanistan.

Also in service with the RAF at Brize Norton are four Trepel Champ aircraft loaders.

champ-140_1

 

Storage

The final piece of specialist equipment for handling aircraft pallets is how they are stored and organised at an air head.

The Air Portable Cargo Handling Dock (caled the Anthony Allen dock), also from AMSS, is in service with the RAF

A complete system of 5 sections and 3 walkways weighs 2.47 tonnes and disassembles to fit on a standard 463L pallet.

Air Portable Cargo Handling Dock

 

The UK company Ban-Air provides many organisations with its 463L pallet storage and organisation system called the Air Pallet Rack

 

Unit Load Device

The term Unit Load Device is a catch all for a collection of pallets and containers used in the civilian air freight business. There is a great deal more variety in dimensions and configurations than with the 463L system as they are often designed to be aircraft specific in order to absolutely maximise volume efficiency.

Airbus_A300_cross_section

Lower deck, main deck containers and pallets will also have different characteristics.

The most common ones are below;

Boeing have a good guide to ULD’s, click here

The RAF’s Voyager and BAE 146 aircraft are able to utilise ULD type containers and pallets;

A330 MRTT 04 Lower deck
A330 MRTT Lower deck
A330 MRTT 06 lower deck
A330 MRTT Lower Deck pallet configuration
A330 MRTT Lower Deck pallet configuration
A330 MRTT Lower Deck pallet configuration

The RAF’s A400M’s will not be configured for civilian pallets, this option was deleted to save money some time ago and the Voyager, without the main deck cargo door and floor will be unable to be used in the mixed or cargo role as other A330 MRTT users are able to.

A330 MRTT Upper Deck cargo version showing pallets
A330 MRTT Upper Deck cargo version showing pallets
A330 MRTT Upper Deck cargo version showing pallets and seating
A330 MRTT Upper Deck cargo version showing pallets and seating
A330 MRTT Upper Deck cargo version
A330 MRTT Upper Deck cargo version
A330 MRTT Upper Deck seating configuration using palletised seats
A330 MRTT Upper Deck seating configuration using palletised seats

ULD’s are loaded and unloaded using much the same equipment as above.

 

 

The rest of the series…

Part 1 – Introduction and General Principles

Part 2 – Pallets

Part 3 – Containers and Flatracks

Part 4 – Container and Flatrack Handling

Part 5 – Boxes

Part 6 – Air Transport Pallets and Containers

Part 7 – Air Despatch

Part 8 – Issues and Solutions for Pallets, Containers and Boxes

Part 9 – Trucks and Trailers

Part 10 – More Thoughts  on Trucks and Trailers

newest oldest most voted
Notify of
DavidNiven
DavidNiven

I wonder if anyone has toyed with the idea of removable rollers fitted to the inside of ISO containers so there is no stripping down of the pallets and cross loading at the other end?

Topman
Topman

Normally plenty of dunnage is used and then, a bog standard fork lift then just move the air cargo pallets. If that’s what you meant?

DavidNiven
DavidNiven

I was thinking more along the lines of pushing straight out of the aircraft into an ISO, but I may be over thinking it as I presume the loads are a mix of various items and not specifically for a given unit. Although could it be done for ammo?

Also is there a reason the pallets are not designed with fork tyne slots (two pallets with slots sandwiched between them?) so as to allow movement with normal forks without the dunnage? or is the fact that they are generally used at established air heads mean that resources are not a problem?

@Monkey

Yes some thing like that :-)

Topman
Topman

Not really an issue as there are broken down anyway, I guess it became the mil standard as it was more suited to cargo a/c. Normally there’s loads of dunnage at any apod anyway.
It would be ideal to have one pallet system, but I don’t think anyone is likely to change, commonality and all that.

Dunservin
Dunservin

Didn’t Maggie Thatcher once fly to the Falklands in a C-130 loaded with a well-appointed, soundproof VIP ISO container?

Deja Vu
Deja Vu

TD Brilliant, I learn so much.

One thing I should like to mention is the whole nause involving Dangerous Air Cargo.

On Ex the old sit up and beg army typewriters were sent to Hong Kong without ribbons (DAC), only to find that BFHK used a different ribbon guage, indeed the standard SO ribbon could not be sourced locally.

Apparently troops and bulk ammunition could not be transported in the same ship, but can in an aircraft. This maybe an urban myth but it was a pervasive one. Any experts available to advise whether true or false.

Anixtu
Anixtu

Don’t know about aircraft, but you cannot legally carry more than (IIRC) 50kg of explosives on a passenger ship. If you were using LSLs, and the operator at the time wanted to abide by the rules, then no, you couldn’t mix troops and ammunition.

We certainly don’t stick to those rules much now.

BigDave243
BigDave243

@DavidNiven.

Your idea of having fork tine gaps between 2 pallets and then not having to use dunnage wouldn’t work in reality because if you were ‘ground dumping’ these aircraft pallets straight onto the ground then there is a much greater risk of the undersides being damaged and by extension damaging the aircraft roller system if the pallet got stuck etc. I’ve dealt with this first hand, and it can be a t**t to sort out.

Good series TD. Although the diagrams used for the Voyager don’t represent how they are loaded or used in reality. Also the standard cargo nets used by the RAF are different from those used by USAF although they are still rated to 9g.

DavidNiven
DavidNiven

@BigDave 243

Cheers I had a feeling I was over thinking it, as well as doubling the price of every pallet for no significant advantage :-)

BigDave243
BigDave243

@DavidNiven

We call it ‘skidding’ the pallet. It does happen, but it’s not the norm, it does have it’s advantages in certain situations though.

↓