Japanese Resupply of Guadalcanal

The Marines have a vision of establishing small, hidden, forward bases inside enemy territory.  From these bases, the Marines will rain death and destruction down upon the hapless Chinese ships (and now subs!).  The bases will be established, resupplied, and, when necessary, relocated by small Light Amphibious Warships (LAW) and all of this activity will remain blissfully undetected by the enemy.

 

Let’s focus on the resupply aspect.  Even if the entire concept were to work perfectly – meaning, that the Marine units could be inserted, establish a base, and launch missiles without being detected – each unit would only be able to launch a few missiles and operate for a few weeks before they ran out of weapons and food.  In other words, in order to be an ongoing threat they must have a means of resupply.  That’s elementary and yet it is an aspect of the concept that has received zero public discussion or explanation.

 

Presumably, the same LAW vessels that would be used to transport and establish the hidden units would also be tasked with the resupply since the presumption is that these miraculous vessels, although slow, defenseless, and non-stealthy, are somehow immune to detection and destruction.  So, we see that a need exists for resupply on a regular basis - every few weeks, presumably.

 

Can this resupply work?  Well, the Marines have hand-waved aside any possible difficulties so that leaves it to us to examine the issue.

 

We’ve already noted the slow, defenseless, and non-stealthy nature of the LAW itself which, for any other platform, would instantly and automatically preclude its survivability and effectiveness in a combat situation.  Had we known that slow, defenseless, and non-stealthy had no negative impact on survivability, we could have saved a lot of money and built the F-22/35 to be slow, defenseless, and non-stealthy and just assumed they’d be undetectable like the LAW … but we didn’t.  Instead, in the world of reality, we know that survivability on the modern battlefield requires speed, stealth, and firepower (which we only sporadically include in designs!).  So for this reason(s) alone, the resupply concept is not viable. 

 

However, let’s dig deeper.  Let’s look where all thorough examinations should look:  history.

 

One of the best examples of contested resupply was the Japanese attempts to resupply their force on Guadalcanal.

 

Initially, the Japanese attempted major resupply convoys escorted by powerful surface groups which led to some of the largest naval battles of the war and resulted in heavy losses on both sides.

 

After those failed, they resorted to smaller efforts by individual ships such as destroyers crammed with troops and supplies.  That, too, failed.

 

The Japanese then attempted resupply using floating supply drums dropped from destroyers.

 

During the Battle of Tassafaronga on the night of 30 November–1 December 1942, the U.S. Navy, at great cost, had thwarted the Japanese navy’s first attempt to resupply Japanese troops on Guadalcanal using the new floating supply-drum method. The Japanese tried again on 3 December, fighting off a 15-plane long-range U.S. air attack from Guadalcanal at dusk and proving that radically maneuvering high-speed destroyers were very difficult targets to hit. The ten destroyers dumped 1,500 drums of supplies just off Guadalcanal, but at dawn, strafing from U.S. aircraft sank most of the drums before Japanese troops could retrieve them. (2)

 

Resupply by submarine was also attempted.

 

The Japanese continued resupply efforts by submarine that had begun the previous month, making three deliveries in the first week of December, before U.S. Navy radio intelligence pinpointed the schedule for the next delivery. In the pre-dawn hours of 9 December, the Japanese submarine I-3 surfaced right between PT-44 and PT-59 waiting in ambush, and was hit and sunk by a torpedo from PT-59 (Lieutenant Jack M. Searles, commanding) which actually worked. Searles was awarded the Navy Cross. The Japanese suspended further submarine supply runs. (2)

 

In addition, resupply was attempted with small landing craft and barges, moving at night.  This gave rise to night battles with US PT boats modified as barge-busting gunboats.

Kinugawa Maru - Beached and Sunk on Guadalcanal Nov 1942

 

Guadalcanal demonstrated that contested resupply is very difficult, bordering on impossible.  The key takeaway from the Guadalcanal example is that almost all of the Japanese resupply efforts were spotted and contested with most efforts failing and this was during a time when sensors were limited to visual range, Mk1 eyeballs in the form of coastwatchers or search/patrol aircraft.  There were no effective radar, IR, satellite, UAV, EO, or other sensors as the Chinese have today.  How we think we’ll be able to resupply the Marine’s bases in the face of modern sensors inside the enemy’s A2/AD zone where the sensor density will be extremely high is a mystery to me and I have yet to hear any Marine address and explain this aspect of the overall concept.

 

  

 

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As a brief reminder, here are some of the characteristics of the Light Amphibious Warship from the CRS report (1, p.6-7) :

 

 

Light Amphibious Warship Characteristics
Length	200 ft – 400 ft
Displacement	4000 tons
Crew	40
Troop Capacity	75 Marines
Cargo Capacity	4,000 – 8,000 sq.ft.
Unloading	stern or bow ramp
Speed	14-15 kts
Range	3,500 nm
Defensive System	25-30 mm gun

 

 

A seemingly minor but incredibly important feature is the use of open deck storage as the main means of cargo storage.

 

The LAW’s maximum draft of 12 feet is intended to permit the ship to transit shallow waters on its way to and from landing beaches. The Navy prefers that the ship’s cargo space be in the form of open deck storage. (1, p.8)

 

This enlarges the vessel’s radar signature, making it even less stealthy and, therefore, less survivable.

 

 

What about cost?

 

The Navy states that it wants the LAW’s unit procurement cost to be $100 million to $130 million. (1, p.8)

 

Given the Navy’s demonstrated inability to even remotely estimate costs correctly, it is a virtual certainty that the cost will be double or triple what the Navy wants.  That puts the cost in the $200M - $390M range.  At that point, these are no longer cheap, throwaway vessels.  Add in the value of the cargo/troops that might be lost with each vessel and the notion of expendable vessels becomes even less viable.

 

 

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(1)Congressional Research Service, “Navy Light Amphibious Warship (LAW) Program: Background and Issues for Congress”, 23-Nov-2020

 

(2)https://www.sofmag.com/guadalcanal-campaign-battle-of-rennell-island-and-operation/