071 LPD thread

[asif iqbal]

Nowhere on the graph does it say that LCU needs 30 handlers and petty officers and that LCAC only requires one deck master and ramp marshalls.

I see the graph as only showing the time necessary for various different LCAC or LCU numbers to transit a distance -- in other words, SPEED. And as I said, this graph uses legacy LCUs with SLOW SPEED, therefore it is invalid with my proposal which is of a HIGH SPEED LCU.

Seriously Blitzo so what I am making things up now? I think I know what I am talking about and not known to make up storys but just for the record

You are suggesting using 8 x LCU in a well deck did you stop to think how much manpower that would take up its not practical

Reference

Department of the navy office of the chief of naval operations

Employment of LCAC US Navy and US Marine Corps

 

[Blitzo]

Seriously Blitzo so what I am making things up now? I think I know what I am talking about and not known to make up storys but just for the record

Reference

Department of the navy office of the chief of naval operations

Employment of LCAC US Navy and US Marine Corps

Okay, please quote me where I said you were making things up. I said nowhere in the graph that you posted was there a mention of crew intensive procedures, which is obviously true.
You should have posted that photo in your original post to back up your claim

But the point still remains -- nowhere in the graph that you originally posted was it said that the speed to transit a distance was related to the labour intensiveness of docking and undocking an LCU or LCAC from a well deck.

That is to say, the graph is still representing the time it takes to travel a distance, AKA speed of transit of legacy LCU versus LCAC. I've been consistent in my posts -- I've always said LEGACY LCUs were SLOWER than LCACs, but that more could be deployed in a single wave.

Therefore, logically, a HIGH SPEED LCU with speed similar to LCAC can also deploy more in a single wave but have transit speeds similar to an LCAC. And that has been one of my rationales for why PLAN should look into high speed LCUs

 

[SinoSoldier]

No that will just won't work

The speed and mobility of a LCAC is it's greatest strength, why make a LCU faster? Why not just use LCAC

It's like me saying I will tune my saloon car to make it more powerful so I can go off road why not just stick to a 4x4??

LCAC holds many advantages over LCU numbers are not always the answer you can always add in another LPD to make up for numbers

LCAC can go beyond just the shoreline, the Type 726 has bow and steam ramps makes reloading quicker and easier, the Type 726 does not need to ballast and deballast it can efficiently can be inserted and turned around, the LCAC can access a much wider range of beeches than a LCU can handle and a LCAC can manoeuvre inland to its primary objective

The whole purpose of being far away from the shore is so you minimise the threat of mines and anti ship missiles you won't eliminate the threat but you will reduce it and reducing a threat is enough in time of war to make all the difference this is why speed, mobility and over the horizon amphibious assault is cornerstone of MEU, China has done a fantastic job with Type 726 shows they are heading in the right direction

That is, of course, assuming that Type 726 is the only available transport they have in the event of a defended coastline. Having a slightly slower but bigger swarm of LCUs allows the amphibious group to evenly delegate strength amongst a vast number of platforms, which provides redundancy in the event of a technical mishap and also greater room for changes in mission/priorities. The decrease in LCU's ability to unload/reload shouldn't matter in a situation where LCACs are safe to use, anyways.

 

[asif iqbal]

LCU are not only slower because of their speed but also to deploy

Even if you had a fast LCU let's say as fast as a LCAC the time it would take to deballast and deploy them would make them inadequate especially if you had 8 squeezed into a well deck when compared with LCAC

So to be clear

LCU slow to deploy and slow speed
LCAC fast to deploy and fast speed

Now let's say we go by your word and say we build a fast LCU they still are slower to deploy so the overall benefit would not outweigh a LCAC, if you then put 4 x LCU well you are back to square one Type 071 LPD already can carry 4 x LCAC so either way this is a non starter

There is a reason why USN operate over 90 LCAC and have a replacement programme in line

 

[Blitzo]

LCU are not only slower because of their speed but also to deploy

Even if you had a fast LCU let's say as fast as a LCAC the time it would take to deballast and deploy them would make them inadequate especially if you had 8 squeezed into a well deck when compared with LCAC

So to be clear

LCU slow to deploy and slow speed
LCAC fast to deploy and fast speed

Now let's say we go by your word and say we build a fast LCU they still are slower to deploy so the overall benefit would not outweigh a LCAC, if you then put 4 x LCU well you are back to square one Type 071 LPD already can carry 4 x LCAC so either way this is a non starter

But you can fit 8 LCUs in the space of 4 LCACs! For example, the british Mk 10 LCU has half the beam of the Type 726 LCAC and a similar length, meaning you can fit twice as many Mk 10 sized LCUs in the space of a set number of type 726 LCACs!

So the options will be:

-4 LCACs: fast to deploy, fast speed
-8 LCUs: slower to deploy, similarly fast speed
-or a combination

Remember asif, I'm talking about storming a beach, where you want to concentrate as much of your landing force in one go. So even if you have LCUs, you can unload all your LCUs and let them wait alongside the LPD first at standoff range, and then let all 8 of them steam in at once to overwhelm the enemy in one large wave.

 

[shen]

I like Asif's point that having a bow AND a stern ramp significantly ease loading. French EDA-R design with mechanically raised and lowered hull seems very complicated. Something like this? but you are still not going to get 30- 40 knts with this. the best none air cushion landing craft can only do mid 20's. you can squeeze all the horsepower you want into the hull, hull resistance is still slowing you down. big engines also reduces load capacity.

[video=youtube;laZ_FSWh-Pk]http://www.youtube.com/watch?v=mreQYZ9p8uI[/video]

and I still don't think you can unify shore based and ship based LCU design. shore based LCU doesn't need the stern ramp. and the superstructure can be higher for better visibility. and bigger of course, not been constrained by well deck size.

 

[Blitzo]

Yep, that BMT design is one I think the PLAN can take cues from, and its fast speed, similar footprint to traditional LCUs, are all inspiration to my idea for a fast LCU for PLAN.

Although it's worth noting many LCU designs have both bow and stern loading ramps. It isn't exactly unique to only to newer LCU designs, rather I'd say lack of bow and stern loading ramps is indicative of a poor LCU design.

 

[Jeff Head]

Well, guys, the US Navy operates two distinct types of landing craft from its large Amphibious Assault ships. And no one has more experience at amphibious landings than the US Navy.

The LCU is larger and carries more equipment and personnel to shore. It also has a much longer range. But it is also a lot slower and takes a larger crew (10 personnel) to operate.

The LCAC is smaller, with less range, a smaller crew (5 personnel), and carrier less equipment and/or personnel. But it is much faster.

The US has thirty some odd LCUs and plans to replace them all. The US has over 90 LCACs and plans to replace them too.

Now, a hybrid LCU, which is marginally smaller perhaps than the existing US Navy LCU, but much faster, is an intriguing idea. I do not believe the US Navy is considering anything like it. However, that is not to say that something like it would not be possible, or even advisable for another military.

Of course, these are landing craft that the US Navy uses off of its LSTs, LPDs, and LHD/LHAs. All of them (outside of the two America class) operating from well decks off of those vessels.

It is interesting to note that the US Army operates 30 some odd LCU-2000s. These are much larger than the LCU-1600 operated by the US Navy, and they definitely will not fit into any well deck.

They displace 1,100 tons, are 175 feet long and draft at 8 feet. Bu they have a 10,000 mile range at 12 knots, and can carry 350 tons (which would include 3 Abrams tanks at once plus infantry. The have a crew of 13.

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[Blitzo]

It is of course worth mentioning that procurement is shaped by needs and production constraints.
Whether the PLAN pursues a Mk 10 sized high speed LCU is one matter, and whether such a design can be built at cost is another. However like you said, it is only an idea that should be examined.

The attraction for me is the ability for smaller Chinese shipyards to rapidly pump out many such ships like they did with 022 (even a high speed LCU would be relatively simpler and less advanced, more conventional, compared to LCACs), thus able to rapidly overhaul the PLANs existing (and disappointing) fleet of small landing craft for regional and possibly TW contingencies, while also providing modern landing craft for LPDs that can be complemented by LCACs in the blue water power projection role.

If Chinese shipyards are able to build a large number of LCACs quickly, reliably and at acceptable cost, and if PLAN had a large number of LSDs to haul LCACs like USN, then I could understand why only buying LCACs may be a more reasonable option.

 

[asif iqbal]

I have had a little think about this and as stated before it would be highly unlikely that a LCU could manage anywhere close to 55-60 knots like a LCAC with a flat bottom hull this would not work

This now further diminishes the need for such a craft so now I do another conclusion

LCU slow to deploy and slow speed
LCAC fast to deploy and fast to run

So that's 2 points for LCAC and 0 points to LCU ( before I was giving LCU 1 point)

If they manage to significantly increase the speed then still I would give it only 0.5 points because it could never be as fast as LCAC which is still less than LCAC which gets 2 full marks

If you are talking about larger LCU then it's a non starter since China has around 30 x LST and 100s of other small utility craft

In in conclusion the scope for LCU in PLAN is very very small