Kapal Pendarat Tank: Perbedaan antara revisi
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== LST Mk.3 ==
{|{{Infobox ship begin}}
{{Infobox ship image|image=File:Lst (3) 3035 FL7209.jpg|caption=HMS ''LST-3035''}}{{Infobox ship class overview|Name=LST (3)|Builders=[[Hawthorn Leslie and Company|R & W. Hawthorn, Leslie & Co. Ltd]], [[Harland and Wolff]], [[Swan Hunter|Swan, Hunter & Wigham Richardson Ltd]], [[Vickers-Armstrongs]]|Operators=*{{navy|United Kingdom}}
*{{Naval|Australia|1913}}
*{{Naval|Greece|royalnavy}}
*{{Naval|Netherlands}}
*{{Naval|India}}|Class before=|Class after=|Subclasses=|Cost=|Built range=|In service range=|In commission range=|Total ships building=|Total ships planned=119|Total ships completed=*UK:
*31 × LST (3)
*2 × LST (C)
*2 × LST (Q)
*Kanada:
*26 × LST (3)|Total ships cancelled=40 + 6 dibesituakan sebelum selesai|Total ships active=0|Total ships laid up=|Total ships lost=|Total ships retired=|Total ships preserved=0}}
{{Infobox ship characteristics|Hide header=|Header caption=|Ship displacement=*2,140 ton ringan
*{{convert|4980|LT|t|0}} muatan penuh|Ship length={{convert|347|ft|m|abbr=on}} [[Length overall|o/a]]|Ship beam={{convert|55|ft|2|in|m|abbr=on}}|Ship height=|Ship draught=*Dengan muatan:
*{{convert|4|ft|7|in|m|abbr=on}} haluan
*{{convert|11|ft|6|in|m|abbr=on}} buritan|Ship depth=|Ship hold depth=|Ship decks=|Ship deck clearance=|Ship ramps=Jalan 23 kaki kali 14 kaki|Ship propulsion=Sekrup kembar, mesin bolak-balik uap, {{convert|5500|hp|abbr=on}}, {{convert|10|ft|m|abbr=on}} baling-baling|Ship speed={{convert|13|kn|lk=in}}|Ship range=|Ship endurance=|Ship boats=|Ship capacity=10 tank ditambah 15 kendaraan|Ship troops=13 perwira dan 150 tamtama|Ship complement=14 perwira dan 90 orang|Ship sensors=|Ship EW=|Ship armament=8 × 20 mm Oerlikon untuk pertahanan A/A di beberapa kapal|Ship armour=|Ship notes=}}
|}
=== Desain ===
Desain LST (2) berhasil dan produksinya ekstensif, namun masih diperlukan lebih banyak LST untuk operasi di Inggris. Oleh karena itu, diputuskan untuk membangun 80 kapal lagi di Inggris dan Kanada yang akan tersedia pada musim semi tahun 1945.
Staf Inggris membuat spesifikasi mereka sendiri, yang mensyaratkan bahwa kapal tersebut:
* Mampu menaiki dan menurunkan tank, kendaraan bermotor, dll, di pantai dengan kemiringan yang bervariasi; dan amfibi dan tank [[Tank DD|DD]] Sherman ke perairan dalam
* Membawa lima [[Landing Craft Assault]] (LCA), atau kapal serupa, dan satu LCT (5) atau LCT (6) di dek atas, sebagai tempat pengangkutan, dan, sebagai alternatif dari LCT (5), dua jalur lintas [[ponton NL]] untuk dibawa; jalan lintas ponton LCT (5) dan NL harus mampu diluncurkan langsung dari dek atas.
* Untuk membawa 500 ton muatan militer dan ke pantai dengan itu serta bahan bakar dan simpanan yang cukup untuk perjalanan pulang pergi sejauh 1.000 mil (1.600 km) dengan kecepatan 10 knot (19 km/jam), pada draft 4 ft 6 in (1,37 m) di haluan dan 11 ft 6 in (3,51 m) buritan.
* Untuk membawa beban seberat enam puluh ton melewati jalur utama dan sepuluh ton melalui jalur kendaraan (yaitu, jalur sepanjang 50 kaki (15 m) dari dek atas ke pintu haluan. Setelah uji coba, beban tersebut dipindahkan dari beberapa kapal)
* Cocok digunakan untuk operasi di daerah tropis dan iklim dingin
Dua masalah besar membuat desain ulang diperlukan. [[Mesin diesel]] [[Electro-Motive Diesel]] 12-[[EMD 567|567]] kecepatan sedang (tipe lokomotif) ringan yang disukai tidak segera tersedia. Staf menginginkan lebih banyak tenaga dan kecepatan lebih tinggi jika memungkinkan, yang dapat disediakan oleh mesin EMD. Namun, satu-satunya mesin yang tersedia hanyalah [[Motor bakar torak|mesin uap reciprocating]] yang sangat berat dari [[fregat]] yang telah dibatalkan. Tenaga ini menghasilkan dua setengah kali tenaga mesin diesel. Saking besarnya, perubahan signifikan harus dilakukan untuk mengakomodasi mereka. Kurangnya fasilitas konstruksi yang dilas menyebabkan lambung kapal harus dipaku. Kombinasi lambung yang berat dan mesin yang berat menghasilkan kecepatan yang hanya 3 knot (5,6 km/jam) lebih cepat dibandingkan LCT (2).
Pada saat yang sama, perbaikan lain juga dilakukan—serta penyederhanaan yang diperlukan agar sebagian besar struktur dapat dirakit dengan [[paku keling]]. Bagian hard [[Chine (berperahu)|chine]] yang telah dijatuhkan pada kapal Mark 2 versi Amerika dipulihkan. Dek tank yang berada di atas permukaan air dibuat sejajar dengan [[Lunas kapal|lunas]], tidak boleh membulat hingga ke dek atas, dan kapal diperbesar untuk menampung mesin yang lebih besar.
Ketentuan dibuat untuk membawa British [[Landing Craft Assault]] (LCA) dalam alat [[Dewi-dewi|gravitasi]], bukan dengan kapal serbu Amerika. Penyediaan juga dilakukan untuk membawa [[Landing Craft Tank]] (LCT) dan [[Landing Craft Mechanized]] (LCM), serta [[jalan lintas]] [[Jembatan ponton|ponton]] NL.
Ketika desain dimulai, para insinyur mengetahui bahwa pantai tempat kapal akan mendarat akan sangat datar, namun tidak mungkin menghasilkan kapal yang memuaskan dengan draft ke depan sebesar 3 kaki (0,91 m), dan kemiringan lunas yang sangat kecil, sehingga kemiringan lunas 1 dari 50 tetap terjaga. Diketahui bahwa kemiringan 1:50 sering kali mengakibatkan LST terhenti di pantai yang dangkal, sehingga kendaraan terlempar ke perairan yang relatif dalam.
Berbagai metode telah diselidiki untuk mengatasi masalah tersebut, namun skeg grounding yang berat dan N.L. jalan lintas ponton akhirnya diterima sebagai standar; jalan lintas ponton dibentuk dari ponton berukuran 7 kaki (2,1 m) × 5 kaki × 5 kaki (1,5 m), dibuat menjadi tali dan rakit. Saat diturunkan, rakit dipasang di ujung depan kapal, dan muatan diturunkan langsung ke pantai, atau ditarik dengan rakit ke pantai.
Kapal-kapal tersebut dipasang untuk layanan dalam kondisi yang sangat dingin dan tropis. Akomodasi yang disediakan untuk awak kapal dan personel Angkatan Darat jauh lebih baik dibandingkan dengan LST (2). Bahaya utama, selain tindakan musuh, adalah kebakaran di dek tank. [[Alat penyiram api]] disediakan, tetapi sistem pembasah air yang dipasang di kapal-kapal Amerika kemudian tidak dapat disediakan.
The bow door arrangements were similar to the LST (2), but the design arranged the bow ramp in two parts in an attempt to increase the number of beaches where direct discharge would be possible. The machinery for operating the bow doors and ramp were electrical, but otherwise, steam auxiliaries replaced the electrical gear on the LST (2).
The general arrangements of the tank deck were similar, but the design increased headroom and added a ramp to the top deck, as in later LST (2)s. Provision was made for carrying LCA on gravity davits instead of the American built assault boats. The arrangements were generally an improvement over the LST (2), but suffered from a deeper draught, and, to some extent, from the haste of construction.
The first orders were placed in December 1943 with British builders, and 35 with Canadian builders. [[Swan Hunter]] delivered the first ships in December 1944. During 1944, follow up orders were placed in Canada for a further 36. These programmes were in full swing when the war ended, but not all vessels were completed.
The ships were numbered numbers ''LST-3001'' to ''LST-3045'' and ''LST-3501'' to ''LST-3534''. ''LST−3535'' and later were cancelled.
Fifteen 40-ton tanks or 27 25-ton tanks could be carried on the tank deck with an additional fourteen lorries on the weather deck.{{sfnp|Rottman|2005|p=6}}
=== Propulsi ===
Steam was supplied by a pair of [[Three-drum boilers#Admiralty boiler|Admiralty pattern]] [[Three-drum boilers|3-drum water-tube type boilers]], working at {{convert|225|psi}}. The main engines were of the 4-cylinder [[Marine steam engine#Triple or multiple expansion|triple expansion]] 4-crank type, balanced on the [[Yarrow Shipbuilders|Yarrow]]-Tweedy-Slick system, the cylinders being as follows:
{| class="wikitable" style="font-size:97%;"
|High pressure
|18.5 in diameter
|-
|Medium pressure
|31.0 in diameter
|-
|Forward low pressure
|38.5 in diameter
|-
|Aft low pressure
|38.5 in diameter
|}
The common stroke was {{convert|30|in|mm}}. The piston and slide valve rods were all fitted with metallic packing to the stuffing boxes, and all pistons fitted with packing rings and springs. The high-pressure valve was of the piston type, whilst the remaining ones were of the balanced type. The main engines were designed to develop {{convert|2750|hp|abbr=on}} at 185 rpm continuously.
With the ships being twin screw, the engines were fitted with a shaft coupling to the crank shaft at the forward end, allowing the engine to be turned end to end to suit either port or starboard side fitting.
=== Modifikasi untuk kapal pendarat ===
When the LST (3)s were ordered, the LST (2) programme was in full swing, and similar arrangements were made to enable the LSTs to carry the {{convert|112|ft|m}} long LCT5 or LCT6 that were being built in America for the Royal Navy.
The LCT needed lifting onto the deck of the ship, being carried on wedge-shaped support blocks; at the time of launching she was set down on the "launch ways" by simply slacking off bolts in the wedge blocks, allowing the launch way to take the weight. To carry out a launch, the LST was simply heeled over about 11 degrees by careful flooding of tanks in the hull. The height of the drop was about {{convert|10|ft|m|abbr=on}}, and immediately after the launch the craft's engines were started and they were ready for operation.
This method was used for moving LCT5s from Britain to the Far East, although there seems to be no reference to LST (3)s being used, most being completed late in or after the war.
Even at the end of the war there was a need for more ships able to carry minor landing craft, and two of the LST (3)s then completing were specially fitted to carry LCM (7). These craft, which were {{convert|58|ft|m|abbr=on}} long and weighed about 28 tons, were carried transversely on the upper deck of the ship. They were hoisted on by means of a specially fitted 30-ton derrick; This 30-ton derrick replaced a 15-ton derrick, two of which were the standard fit of the LST (3). The 30-ton derrick was taller and generally more substantial than the 15 ton one.
The LCM (7)s were landed on trolleys fitted with hydraulic jacks. These ran on rails down each side of the deck, and were hauled to and fro by means of winches. The stowage was filled from fore to aft as each craft was jacked down onto fixed cradles between the rails. The ships completed to this standard were ''LST-3043''/HMS ''Messina'', and ''LST-3044''/HMS ''Narvik''. While these ships were able to carry LCMs, they were only able to carry out loading and unloading operations under nearly ideal weather conditions, and therefore could not be used for assault operations; they also lacked the facilities to maintain the landing craft (which the Dock Landing Ships provided).
The Landing Craft Assault were wooden-hulled vessels plated with armour, {{convert|41|ft|6|in|abbr=on|m}} long overall, {{convert|10|ft|m|abbr=on}} wide, and displacing 13 tons fully loaded. Draught was {{convert|2|ft|3|in|abbr=on|m}}, and normal load was 35 troops with {{convert|800|lb|abbr=on}} of equipment. A pair of Scripps marine conversions of Ford V8 engines gave it speeds of {{convert|11|kn|km/h}} unloaded, {{convert|8|kn|km/h}} service speed, {{convert|3|kn|km/h}} on one engine. Range was {{convert|50|–|80|mi|km|-1}} miles on {{convert|64|impgal|L}}. Armament was typically a [[Bren light machine gun]] aft; with two [[Lewis Gun|Lewis Guns]] in a port forward position.
The LCM (7)s that were carried on the LST (2) were considerably larger, {{convert|60|ft|3|in|abbr=on|m}} in length, {{convert|16|ft|m|abbr=on}} beam, with a hoisting weight of 28 tons, full load displacement of 63 tons. Beaching draught was {{convert|3|ft|8|in|abbr=on|m}}, and propulsion was provided by a pair of Hudson Invader petrol engines, later replaced with Grays diesels, both sets providing {{convert|290|bhp|abbr=on}}, giving a speed of {{convert|9.8|kn|km/h}}.
The main requirement of the design was to carry a 40-ton [[Churchill tank]] or bulldozer at {{convert|10|kn|km/h}}. 140 had been completed when the war ended, and some saw service through to the 1970s.
=== Varian ===
Some LST (3)s were converted to LST (A) (A for "assault") by adding stiffening so they could safely carry the heaviest British tanks.
Two LST (3)s were converted to command vessels, LST (C): LST 3043 and [[HMS Narvik (L3044)|LST 3044]]. Post war they became HMS ''Messina'' (L112) and HMS ''Narvik'' (L114). They were better armed with ten 20 mm Oerlikons and four 40 mm Bofors.
Two LST (3)s were converted during building into Headquarters command ships LST (Q). These were L3012, which became L3101 (and later HMS ''Ben Nevis'') and LST 3013, which became LST 3102, and then HMS ''Ben Lomond''. They acted as LST "mother ships", similar in most aspects to American ships based on the LST (2) hull. They had two [[Quonset hut|Quonset huts]] erected on the main deck to accommodate 40 officers. Berths on the tank deck berthed an extra 196 men. A bake shop and 16 refrigeration boxes for fresh provisions augmented the facilities normally provided for the crew. Four extra distilling units were added, and the ballast tanks were converted for the storage of fresh water.
== Layanan dalam Perang Dunia II ==
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