article promoting the US Merchant Marine

[Ivanhoe]

https://gcaptain.com/logistics-wins-war-in-the-pacific/

Quote

In conclusion, the US Marine Corps has made the decision to divest from heavy equipment such as tanks and large prepositioning ships, in favor of lighter and more mobile forces that are better suited for modern threats and operational environments. The Corps has been shifting its focus towards naval expeditionary warfare, which emphasizes the ability to rapidly deploy forces from ships to land and conduct amphibious operations. This has led to the proposal of a new type of ship design – the Light Amphibious Warship (LAW) – that’s smaller, faster, and cheaper to produce than big deck amphibs. Additionally, the article suggests that to achieve greater speed in ocean combat logistics, the US and its allies also need a greater amount of smaller, lower-cost proposition and sealift ships, capable of steaming at higher speeds. By adopting such an approach, the US could improve its logistics chains and better protect its forces in the event of a conflict.

One logical weakness is the claim that "While the Air Force may be able to move light equipment quickly, its entire fleet of cargo planes combined can carry less cargo than a single modern containership."

While probably true, for a battlezone which takes a containership 20 days to transit, cargo planes can get at least 10 turns. Need both.

[futon]

Rather lengthy article. To compliment it, this video. Speaker is skeptical about the LAW which is pretty much an LST. Skepticism about a fast design that can get up an on the beach. Required specs 4000 tons, but still just 14, 15 knots? 35 of them, first to start commissioning by 2029 (alpha estimate with accepted delay naturally so 2031 or w/e).

Idea of littoral marines bouncing around the 1st island chain on these LAWs comes from an earlier idea of bouncing around arty off from C-130s. But C-130s are fast. 15 knots is not. And beaching is a slow process. One design idea would have jack legs that press agaisnt the coast bottom to stablize the ship for off loading from a big ramp. Anyway, the big flat deck amphibious assault ships would hang back to protect lines of communication. I guess an extension to that idea is to use them as mini carriers with F-35Bs. Anyway..

 

Edited March 12 by futon

[Ol Paint]

On 3/11/2023 at 9:21 AM, Ivanhoe said:

https://gcaptain.com/logistics-wins-war-in-the-pacific/

One logical weakness is the claim that "While the Air Force may be able to move light equipment quickly, its entire fleet of cargo planes combined can carry less cargo than a single modern containership."

While probably true, for a battlezone which takes a containership 20 days to transit, cargo planes can get at least 10 turns. Need both.

That’s a disappointingly poorly-written article about a subject that is both complex and in dire need of correction.  The article glosses over myriad issues and presents some ideas that appear to lack supporting analysis and logic.  The subsections are disjointed and the article never seems to tie the pieces together.

As for the claim that the entire US airlift fleet does not equal the tonnage of a single Maersk containership, that’s not a great metric because megacontainerships have no meaningful self-unloading capability, which would be an issue in the event of sustaining a conflict in the Far East.  The issue of port facilities is one of the reasons the RRF tended to favor RORO vessels and has tended to maintain a stock of general cargo ships and crane ships in the past (now being scrapped).  A better comparison would be between the logistics ships maintained by the Military Sealift Command and the airlift fleet.  So, what does the Air Force have to offer and how does it compare to the MSC fleet?

C-17       164900lb (74LT) to 2400nm per AF.mil  223 Airframes  Cruise speed approx 450kt

C-5M     281,001lb (125LT) to 2150nm or 120000lb (54LT) to 5524nm per AF.mil  52 airframes  Cruise speed approx 450kt

C-130J   ~35000lb (15.7LT) @ ~2000nm (varies depending on model) per AF.mil  171 J models plus 162 earlier models, but we’ll be generous and pretend they are all J models.  Cruise speed approx 365kt

I didn't include the KC fleets (KC-135, KC-10, KC-45) since they will likely be occupied with refueling duties.

Large Medium Speed Roll-on/Roll-off (LMSR) = 33831 tons (30206LT) @ 24kt 19 ships (T-AKR 300/310 classes plus 4 additional) NVR

Algol-class LMSR = 32395tons (28924LT) @ 32kt 8 ships NVR

Distance (straight line) from Los Angeles, CA, to Manila, PI:  7300 statute miles or approximately 6300nm per Google Maps.

Basic numbers, not counting fuel stops

1 T-AKR 300/310-class LMSR delivers 30,206LT in 262.5 hours or 115LT/hr per ship

1 T-AKR 287 Algol-class LMSR delivers 28924LT in 197hrs or 146.8LT/hr per ship

19 LMSR + 8 Algol = 2185LT/hr + 1174.4LT/hr = 3359.4LT/Hr

Assuming all ships leave simultaneously, these 27 ships will deliver 805,306LT after 262.5 hours.  I'll use this as the baseline increment.

C-17

6300nm / 450kt = 14 hours flying time for 5.3LT/hr per aircraft one-way.  But since we are going to compare multiple crossings of aircraft, the delivery per flight hour is halved since the return leg is essentially empty.  So 2.65LT/hr.  We’ll have to do the same for shipping if we assume continuous logistics, which I’ll address below.

223 aircraft *262.5hrs * 2.65LT/hr = 155,124LT

C-5M

6300nm / 450kt = 14 hours flying time for 8.9LT/hr per aircraft one-way.  For multiple crossings, the delivery per flight hour is halved.  So 4.5LT/hr. 

52 aircraft *262.5hrs * 4.5LT/hr = 61,425LT

C-130 (included to help inflate the airlift side of the equation)

6300nm / 365kt = 17.3 hours flying time for 0.9LT/hr per aircraft one-way.  For multiple crossings, the delivery per flight hour is halved.  So 0.45LT/hr. 

333 aircraft *262.5hrs * 0.45LT/hr = 39,336LT

Total Tonnage

Total Tonnage
262.5hrs 	Airlift = 255,885LT	Sealift = 805,306LT
525hrs		Airlift = 511,770LT  	Sealift = 805,306LT
787.5hrs	Airlift = 767,655LT	Sealift = 1,610,612LT
1050hrs		Airlift = 1,023,540LT	Sealift = 1,610,612LT
1312.5hrs 	Airlift = 1,279,425LT	Sealift = 2,415,918LT
1575hrs 	Airlift = 1,535,310LT	Sealift = 2,647,310LT

I ran it out to 1575 hours because the faster Algol-class vessels will have completed an extra crossing at that point due to their faster speed.  This will start widening the tonnage delivery gap even more.  All of this assumes 100% availability, no factors for turn times, no factors for port/airfield throughput, etc.  It's just back-of-the-envelope.  And we haven't started to include the delta in procurement and operation costs.  At a ballpark $500 million apiece for each ship, the total fleet cost for 27 ships is $13.5 billion.  At a generous $100 million/plane, the 610 airlifters cost in the neighborhood $61 billion.

The Joint High Speed Vessel, or Spearhead-class EPF has a range of 858nm at 31kts carrying 535.7LT (600 tons) (Source).  It can self-deploy, but that’s not enough range with payload to play in the strategic sealift/airlift arena in a meaningful manner. 

Airlift has the advantage that it is more difficult to intercept and the loss of any single asset has less impact on the overall picture.   On the flipside, the average airlifter is using a crew of 10-12 (crew rest issues) for a total ~6000 aircrew, not to mention the squadron support personnel.

Comparatively, the shipping is more vulnerable to interception and the loss of each vessel has a large impact, but the manpower to operate the fleet is much smaller.  The T-AKRs have a complement of about 45 personnel for 1215 total over the 27 ships.  So 20% of the personnel are delivering 57% more tonnage. 

Doug

(Edited to correct formulas)

Edited March 12 by Ol Paint

[DB]

The turnaround times for the aircraft are likely to be a larger fraction of the transit times so likely make the numbers look even worse. On the other hand, first assets arrive on the first day, so maybe there are still ports for the Ro-Ros to dock at when they do show up...

[Angrybk]

As an aside, US Merchant Marine is like the best blue collar job ever. Bust ass for several months and then get several months off.