Supply flow demands and logistics lorry versatility

.
I addressed this before, but this time I'll try to make my point in greater detail:

“Truck transport, which supports delivery of material resources, supplies of lubricants (POL), ammunition, etc., comes in companies for regiments and in material-technical support battalions for brigades and divisions (RMO and BMO). Each company (or platoon) answers for conveyance of a concrete item. For example, the first company of a BMO (or platoon of an RMO) transports ammunition, and the fifth, equipped with tankers, transports fuel.”

(quote from Russian Defense Policy blog)

This was not an uncommon approach historically, and even today such specialisations are still visible on military logistical vehicles everywhere, though not necessary in order of battle. I think it's a wrong way of doing business.

I'm not in the mood to search through logistics field manuals, so I'll quote Dunnigan on the reason why this is so wrong:
 
Divisional daily supply requirements*
U.S. infantry division

	Offense	Defense	Pursuit
Ammo	2,500	3,500	410
Fuel	1,210	671	1,496
Food	51	49	50
Spares	55	50	44

We can see a basic supply flow capacity requirement for

about 700 tons fuel/day

+ about 500 tons ammunition/day

+ about 100 tons other supplies/day.

In addition to this a supply flow capacity for about 3,000 tons ammunition/day or 800 tons fuel/day should be satisfied. This would be possible with about 200 heavy lorries.**

A 8x8 lorry such as MAN 15 t mil gl MULTI (a 1990's design) has a payload of 15 metric tons (not really that much in difficult terrain, of course) and can use MULTI racks (~DROPS for British, ~PLS for Americans). The racks can be ammunition racks (especially for 120 mm tank or 155 mm artillery ammunition) as well as fuel tank racks with about 8.5 tons diesel fuel each:

(I ignore the existence of 14,000 litres fuel tank racks because the extra 3,000 tons ammunition/day requirement is the bigger headache anyway and more fuellers equals quicker refuelling.)

100 of these lorries would suffice** for the peak fuel demand, and 200 (or with less than 15 tons fitting on a rack maybe about 300) for the peak ammunition supply demand.

So by having at least some of your logistics capable of a quick change between ammunition and fuel supply you may reduce your need for heavy lorries by about 15 % assuming that the bulk supply transportation is being done by heavy, not medium, lorries:***

About 130-150 heavy 8x8 lorries to meet basic supply flow requirement.

100 MULTI and 100 flat rack or 200 MULTI heavy 8x8 lorries to meet peak supply flow requirements.

Alternatively, the latter could be met under the same circumstances with about 60 dedicated 8x8 fuel lorries and about 200 MULTI and flat rack heavy 8x8 lorries.

You can save those 60 dedicated fuel lorries by increasing the versatility in the Tables of Organization and Equipment (one company in dual role with.MULTI lorries). Alternatively, you could still have those 60 extra lorries and thus have about 17% extra capacity reserves (and thus more reliability of resupply) in the supply flow system.*****

This extra in reserves and the gain in versatility might weigh heavily if the supply movements are disrupted and lorry attrition becomes a relevant factor. There's no reason to fully trust the supply demand expectations anyway, so having about 17% more capacity would be reassuring.

Some readers might think the peacetime inventory of military logistical trucks won't cut it anyway, they would only carry and accompany the troops, whereas the hauling from depot, harbour, airport or railhead to  the brigade in the field would need be done by civilian trucks anyway. Yet even under this assumption, the extra role versatility would matter, for a brigade commander might want to build carried stocks of diesel fuel in expectation of the next two days, and afterwards might want to build up carried stocks of ammunition.

Now the sad part of the story: As far as I know the Bundeswehr has still purchased only troops testing-scale quantities of fuel tank racks. This is one of the nowadays typical miniature army procurement programs that afflict non-sexy programs (such as army air defences, mortar systems, guided artillery rockets, MULTI racks in general etc.) in today's Bundeswehr and point at a structural problem the (quasi-)political leadership should be held responsible for.

S O

defence_and_freedom@gmx.de

*: This was quoted from the 4th book edition of 2003, the 1st was published in 1982. The data still shows the principle.
**: I assume one trip back and forth per day and have little reserves for lorries not in working order. All lorry figures could be multiplied with a factor to meet different expectations; the general reasoning would not differ.
***: This should be the way to go, to cut down the need for vehicle and driver quantity.  15 metric tons payload is actually not much compared with civilian lorries.
****: It should also be possible to pause the resupply with food for several days in a row, considering how many rations can be carried in motor vehicles. This saves but four lorries per division, though. The bigger saving would be in reduced hassle with the distribution of the food during mobile warfare.

I did treat Dunnigan's "tons" as metric tons here, but again, what kind of "ton" he meant doesn't affect my case here. 

10 cubic metres of diesel fuel = about 0.85 metric tons of diesel fuel.

In case you're interested in military lorries, trailers, containers and engineer machines, you might do well to periodically look up whether any "Jane's Military Vehicles and Logistics" yearbook is available on ebay. I got my 2004/2005 edition years ago for a price of 20 €.

It should be noted that flatbed lorries inherently have the dual-use versatility; fuel drums or ammunition pallets can both be loaded. Fuel drums aren't the way how 'we do business' any more because handling and refuelling are awkward and slow. Fuel bladders / fuel pillows / flexible fuel tanks are slow to load and fixate, but some models are designed so a tank can self-refuel with them by creating the necessary internal pressure by driving onto the fuel bladder. I'm not making this up! Still, handling is 'awkward'. 

.