Where is your evidence for this. The hull is not cheaper. For the same size steel hull you would pay much less for both materials and construction. Price welding material for aluminium welding at your local hardware store and compare it to the cost of materails for mild steel. Have a look at Fairplay solutions for ships costs and you will find that an 127m aluminium HSC vessel is more expensive per tonne than a mild steel general cargo or even bog standard tanker hull by a number of mulitples depending on the fit out.
Just for clarity. What is meant here is cost per tonne uplift has an incredibly higher cost on a HSC hull compared to a steel hull of the same length.
The 127m trimaran ferry has a DWT of 400 to 450 tonnes (depending of figures) on 127 m. This includes:
fuel (ships bunkers)
stores
crew ...... and
cargo (250 PAX and 1000 cars)
This is a miniscule mass for the ship size and given the ship (including propulsion, auxillaries and systems) are not cheap so the cost of lifting limited weapons is proportionally very high. For LCS the same hull must support the standard weapons pack, mission modules and helecopter. Due to the nature of the hull it will have close to zero displacement growth potential (hence the use of mission modules to provide flexibility).
For a frigate version of the same hull any change in weaponary and/or systems must be at the expense of somthing fitted if it adds weight.
I love the GD web site indicating the great air asset capcity of the LCS wiht one C-53, two S-60 and up to 6 ROV (look like fire scout). Using max TOW on these assest you get
1 x C-53: 33 tonnes
2 x S-60: 20 tonnes
6 x MQ-8B: 9 tonnes
So the ship has used up 62 tonnes (15% of DWT) before it has loaded crew, stores (including food and water), bunkers for the ship and Jet A1, ammunition for ship and aircraft etc. This assumes that the LCS can stay within the light weight of the 127m ferry which I have some doubts about. In fact the tonange allowed for mission packages on LCS with a standard weapns fit is only 180 tonnes of which 75 tonnes is fuel. I suggest aircraft are mission packages and I suggest carrying all the aircraft listed above will limit the ability of the LCS to do anything else, or even do this for very long.
Another comparision. According to naval technoligy the ANZAC (which is a smaller combatant) has a full load dispalcement of 3600 tonnes on 118m LOA. USS Freedom at about the same length only has a displacement of about 2500 tonnes. To achieve the speed the weight reductionis vital but it comes at a cost in carrying capacity in respect of mass and limits range (even at cruising) with a published range of 4500nm which in the Australian context is not much. Hit the power and the range will plummet. In other LCS will need more support from other units both for defensive purposes and logistics support and that appears to be how the USN will operate them.
As for the frigate version noting the Mk41 8 cell module will weight 24 o 26 tonnes loaded adding 3 to 4 of these to the ship will addd up to 100 tonnes
before we look at the two CIWS, Medium calibre gun, AEGIS (including directors) etc.
Sorry unless the extend the hull this thing will have pretty significant weight limitations on load out. Even extend it willnot lift as much as nor hull of the same LOA.
Finally both LCS designs are based around sea state 5. Sea state 5 is a "fresh breeze" with wind speed of 17 to 21 knots. Fromt he land perspective "small trees in leaf begin to say" ....
http://www.uscg.mil/hq/g-m/risk/sea_state_2.htm
We are not talking about much with a wave height of 4 to 6 feet. A quick look at "Ocean routes of the world will show that much on much of the globe there is greater than a 10% change of 12 feet for much of the year.
It is much worse from about 30S around Australia. This is not an issue for LCS in litorial waters, which are normally sheltered, but if the growth constrained frigate version were to replace surface combatants this is a major issue.
I will now get off my hobby horse
