Yes and that is called ship to shore. The Australian Army however has additional coastal and inland waterway missions for its LCMs that require extra range. I have made this difference clear from post no. 1 on the topic. I don’t understand why you’re making a big deal out of it. Accept that the Australian Army will want a LCM with sufficient range for all of its missions. The LCM-1E can do the ship to shore mission (about 1/3 of the force) but not the remainder.The job to be done by Lcm1e, to deploy from over the horizont wrt the beach, is well acomplished with 190 nm range.
The LCM-1E can only make 13.5 knots with a 56 tonne load, with 100 tonnes onboard it can only make 9 knots. Your time to shore comparison does not include the two hours it takes to ballast down the LHD so the LCMs can float in and out. Using M1A1 tanks as a load benchmark (62 tonnes) it takes just over four hours for the first wave of four LCM-1Es carrying M1 tanks to hit the shore.The Lcac speed with payload is 40 knots wrt 15 of Lcm1e, so say 3 times faster (incl. load/unload time), a normal load on Lcac of 50 t. for 2 Lcac is 100 t. times 3 is 300 t., while in that time 4 Lcm1e has put say 70 t. normal load (distributed) times 4 is 280 t. so my numbers don´t out perform Lcm1e by a significant margin (just 20 t., talking about distributed load), maybe yes in fuel burnt :lol2
During that time LCACs carrying M1 tanks can offload three waves to shore or with two LCACs per wave six tanks. Which is more than the four tanks the single wave of LCM-1Es can achieve. The LCACs have the benefit as well as being able to cross three times more littoral zones than the LCMs which need a sharp sloping beach. Plus the LCACs have little problems with returning to sea as they don’t get beached and their tanks are delivered totally dry to the hard earth.
I understand what you are trying to say but it just doesn’t add up to the real data. The LCAC can put 50% more armour ashore even when outnumbered two to one.But is important the first wave is heavy armoured enough, whenever you decide to reach the beach that important first touch of the beach in distributed in 4 different landing points with 4 Lcm1e and more those 200-260 t. more to be able to defence themselves. I hope i explain well, until the 2nd wave arrives.
My data is from the Navantia brochure and it details the various speeds, sea states and load conditions of the LCM-1E. With the full 100 tonne overload it isn’t really something outside of harbour conditions and certainly no surf zone. It is clearly customised for the 56 tonnes load – the Spanish Marines M60 tank – but can carry the Leopard II but at a penalty in speed, sea worthiness and landing ability.I don´t know where you get your info, but Lcm1e is was designed to lift a Leopard tank of more than 60 t. to complete that full misssion. The 100 t. is "overload" what it means it wont be able to carry that on high state easily, but yes in good state, similarly the figure 70 t. for Lcac is also "overload" and i don´t think is not affected by sea state if this is bad enough, as you say.