Amphibious Loading Error

[Sid]

Although I am generally impressed with the UV logistic system, I begin to suspect there are real problems with details. I sent 4 APDs with a regimental combat team to Tulagi. Although none survived the trip, they managed to deliver 758 men, 2 155mm howitzers, 8 105 mm howitzers, 8 37 mm AT guns and 8 mortars!!!! My first ship was a WWII type APA and I worked with an actual WWII era APD LARGER than existed in 1942. There is NO WAY to put a 155 on an APD! And there is NO WAY to put more than 150 men (=600 for four ships) on one! Aside from the fact that my ships lost some of their men, they must have carried more like 200 men each. IF you put 8 105s on 4 of these ships, you would have a SUBSTANTIAL penalty in the men they could usefully carry -- and I am not sure if it is physically possible -- in spite of great imagination in this sort of thing. It is NOT US doctrine to attempt to do so. An APD carries ONLY light infantry with NO heavy weapons in this class!!!!!!!

[dgaad]

APDs were of varying sizes and shapes. The most common APD was built on a destroyer escort frame, with a designated storage capacity of 4 pack howitzers, as well as 162 men, and 6,000 cubic feet of ammo storage (which is about 3 times the size of the average US house).

Some APDs were built on destroyer frames and consequently much larger in terms of storage capacity. ALL of the APDs at the start of the game are of the destroyer variety, rather than the destroyer escort variety. Also, keep in mind that even 155s had a disassembly/reassembly procedure for transport.

The APDs based on destroyer escort frames were more commonly built later in the war, so they would have been smaller. Also, both destroyers and destroyer escorts that were designated as APDs were usually fitted with an additional deck precisely for transport purposes.

Here is a photograph of a ship in the game, the USS Colhoun.



This ship was sunk during the Guadalcanal operation.

[1089]

The salient point, I think is that the APD's were all sunk, yet delivered almost all their cargo. This was an annoying thing in PacWar, and I had hoped it was not in UV. Apparently it is.

kp

[dgaad]

Originally posted by 1089
The salient point, I think is that the APD's were all sunk, yet delivered almost all their cargo. This was an annoying thing in PacWar, and I had hoped it was not in UV. Apparently it is.

kp

The original poster did not indicate that this was the salient point, nor did he specify whether they were sunk prior to delivery, or just after. APDs will proceed to target, unload, and proceed back to the originating hex, all in one turn if sufficient ops are left.

[Erik Rutins]

What sank the APDs? If it was a surface battle, that could easily have happened on their outbound leg while in the base hex. I know such checks are made inbound and outbound if an enemy TF is in the hex looking for them.

Regarding the capacity, I'm no expert on this but it sounds like both Sid and Dgaad have some good info that's in conflict. Sid, were you on one of the smaller DE types?

Regards,

- Erik

[Sid]

USS Calhoun WAS on a "destroyer frame" alright, but a WWI destroyer frame, and she could carry less than the later APDs. She also was converted in 1942, and not available on 1 May in the South Pacific. Something is very wrong with this picture! In any case, it remains US doctrine NOT to transport even light artillery via APD, and IF they did, they could not ALSO transport infantry. Why is this so hard to get right?

[dgaad]

Originally posted by Sid
USS Calhoun WAS on a "destroyer frame" alright, but a WWI destroyer frame, and she could carry less than the later APDs. She also was converted in 1942, and not available on 1 May in the South Pacific. Something is very wrong with this picture! In any case, it remains US doctrine NOT to transport even light artillery via APD, and IF they did, they could not ALSO transport infantry. Why is this so hard to get right?

Sid : Did I say that the Calhoun was a large or small ship? That is was based on a WW1 or WW2 hull? No I did not. I just offered the picture to give a general idea of the size of these TYPE of ships, thats all.

Anyone who wants to know all about APDs and many other types of US ships in WW2 should check out

Navsource.org

which contains a listing of virtually every ship used in WW2, along with a brief history of each ship. This includes ships as lowly as destroyer escorts.

As you will see, a GOOD NUMBER of APDs have storage space for pack howitzers, as indicated in the ship specifications which specifically refers to storage space for these guns, and a very massive number for ammunition storage. I'm sure from reading through the history of each and every APD you will find that in some cases they did transport more than just men and rifles, but guns as well.

[Kadste]

For further reading try:

http://www.usmarineraiders.org/creatingraiders.html

"Since the APDs could neither embark nor offload vehicles, that meant the battalion had to be entirely foot mobile once ashore, again like the parachutists. To achieve rapid movement, Edson recommended a new table of organization that made his force much lighter than other infantry battalions. He wanted to trade in his 81mm mortars and heavy machine guns for lighter models. There also would be fewer of these weapons, but they would have larger crews to carry the ammunition. Given the limitations of the APDS, each company would be smaller than its standard counterpart. There would be four rifle companies, a weapons company, and a headquarters company with a large demolitions platoon. "



and

http://www.usmarineraiders.org/shapingraiders.html

"To keep manpower within the constraints of the carrying capacity of an APD, each rifle company had just two rifle platoons and a weapons platoon. "

There is more on each page.

Really points out hte limitations of the APD's that are represented in UV.

[dgaad]

Kadste : sorry, but there were a number of APDs that has loadout specifications for jeeps and trucks. You simply cannot take one or two paragraphs from one or two APDs as representative of the entire class, they came in many shapes and sizes with different cargo capacities and cargo spaces.

It does not surprise me in the least that the APDs used for Raider operations were smaller ones which had no cargo spaces for jeeps, trucks, or heavy weapons. Raiders almost never had a need for these types of items for their operations, so it would have been a waste to assign a larger APD to a Raider unit for operations.

[dgaad]

Originally posted by Sid
USS Calhoun WAS on a "destroyer frame" alright, but a WWI destroyer frame, and she could carry less than the later APDs. She also was converted in 1942, and not available on 1 May in the South Pacific. Something is very wrong with this picture! In any case, it remains US doctrine NOT to transport even light artillery via APD, and IF they did, they could not ALSO transport infantry. Why is this so hard to get right?

From Navsource.org :

"Converted to a Dent Class High-speed Transport and Recommissioned USS Colhoun (APD-2), 11 Dec 1940"

One really should make use of available historical sources before proclaiming facts.

[Kadste]

dgaad,

I think that you should look into this a little more. Were talking about 1942 not 1944-45 when the US had many types of APD's. Big ones, little ones, some could carry equipment, some could not.

During the early period of this game APD's carried troops and supplies. Most of the time they carried a company of troops. They carried occupation troops for Viru anchorage, then raiders to Bariroko harbour. Also used for Vella Lavella where they along with 12 LCI's and 3 LST's carried 4600 troops, including the 64th Field Arty Bn and the 4th Marine Def Bn. If APD's could carry equipment, why use the Large Slow Targets? Used in the Treasuries to land the 2nd Para Bn. 4 of them were used to land 725 troops. Not used in the landings at Empress Augusta Bay, troop rode in style in APA's. Were used in the second echelon though, with LST's. Also used in subsequent echelons, but again with LST's.

Used at Arawe, with LSD's. The APD's were used to land Raiders, who were to land first in rubber boats. They were also used at Cape Gloucester, with a ton of LCI's, LST's, LCM's, and LCT's. They carried Bn landing teams. 10 APD's were used to carry 1440 marines.

APD's were part of the operations to capture Green island, again with LCT's and LCI's.

Also used in the assault in the Admiralties. APD's and DD's carried the first troops troops to land. This was a reconaisance in force, quickly reinforced with heavy troops.

Now I am no expert on APD's, but in reading from many sources on operation in the South Pacific during this time period, APD's seemed to play a supporting role, not a role that they could assume if they carried the heavy equipment (jeeps or trucks), unloading would be very cumbersome as they had no ramps to facilitate quick unloading. Actually the LST was a pig to unload, but used most of the time because it could carry almost anything. If APD's could carry equipment, why the LST's?

If there are sources out there for this time period that mention that APD's carried other than light equipment, please let me know, they are pretty scarce. Most sources mention them carrying troops or men.

And do not forget that the first APD's were converted for the purpose of carrying raiders, not heavy equipment.

[Kadste]

dgaad,

You are right in the fact that the Calhoun/Colhoun (spelling found in different sources, but both refer to APD-2) was converted to APD-2 and recommissioned in Dec 1940.

Sid was refering to the fact that she was not available on May 1, 1942. He is right, The Calhoun/Colhoun arrived in the South Pacific in July 1942 and subsequently helped in assault on Tulagi.
Sunk in August 1942.

Here is a picture of here with an LCA in her davits.

Not sure where you would put a jeep or a truck or a 155 or even a 105.

[dgaad]

Why do I keep getting the feeling that no one reads what I actually said, and instead assumes I said things I did not.

I did NOT say the Colhoun had the space to carry trucks.

I did NOT say the Colhoun was ready and available in theater in May, 1942.

Sid DID say the Colhoun was not CONVERTED to an APD until 1942. He was wrong about that. Read what he said.

I am no longer going to post in this thread if my words are unread, and other words are substituted as being mine.

[Erik Rutins]

Sid,

The designers and developers read these forums and your questions on APDs have been noted.

Regards,

- Erik

[Sid]

A simulation is of necessity simplified from reality. There may indeed be some theoretical possibility that even rarely got used by someone. But there is also the general rule, and that is what a simulation is supposed to force you to do. In the case of the APD there is the DESIGN INTENT that it is for quick in and out of raiders - it is FAST - and it does not carry disassembled howitzers for the reason that there is no time to assemble them going in or take them apart when leaving.

If you are going to accept what was done as the sole argument, then reclassify the F1M2 Pete as a "fighter bomber." It was INTENDED to be a recon float plane, but its rugged construction made it an effective fighter bomber (albiet with a light bomb load). It also racked up a true score of victories in the fighter sense, which a normal observation plane could not do. It is irritating that this plane cannot be used as it was, if not often, than more than rarely.

As to the APD, I assure you, the idea in the USA was they are only for light infantry. I admit one theoretically might load something else, but the cargo is too small to be of interest for moving a combined arms force of any size.

Also, 4 APDs should not be able to deliver more men than can fit! They are amazing ships - they sleep troops in the passageways no less. There is quite literally no room to overcrowd them -- they are filled to the gills for short runs. For a long trip, the APD goes empty, or partly filled, so men can tolerate conditions.

[Rich Dionne]

Sid,

I will be adjusting the Colhoun's Noumea arrival date to 21 July 42, and we will review the carrying capacity of the APD. Unfortunately, with a game of this scale, some errors are inevitable, but we will do our best to correct them.

Regards,

Rich Dionne

[dgaad]

Since no one reads what I say, perchance listen to what others in greater stead of history do :

"The US Navy converted a number of destroyer escorts to high speed transports (APD). Some ships were converted during the building process and others converted after having first served as a destroyer escort. The DE was not the only type ship to be converted to a APD. WW I type (four piper) destroyers were altered to have light troop transport capabilities. APD hull numbers 1-36 were converted destoyers.

APDs were created by two opposite but complementary situations. The first was a need for light transports with relatively shallow drafts and a capacity to move light army or marine units rapidly to myriads of Pacific islands. The second was a growing excess of DEs in the Atlantic, permitting several to be converted.

To the DE, another deck was added along with troop berthing and messing accommodations. A very large davit was installed on either side, each of which could launch and recover two 36 foot assault landing craft (LCVP). It could carry underwater demolition teams (UDT) or move troops, supplies, light trucks and jeeps to and from the staging areas.

The 3"/50 caliber main battery was replaced with a more efficient destroyer type 5"/38 caliber gun forward in a movable mount. Torpedoes, hedgehogs and Kguns were removed. (1)

Major Characteristics
Length Overall: 306'
Extreme Beam: 37'
Trial Displacement: 1,650 tons
Limiting Draft: 12'7"
Trial Speed: 23.6 k

Accommodations
Ship's Company: 12-15 Officers, 189-192 Enlisted
Troop Capacity: 12 Officers, 150 Enlisted

Armament
Gun Mounts: (1) 5"/38 single, (3) 40mm. twin

Engines
Manufacturer: GE
Type Drive: Turbo-Electric (steam)

Propulsion
2 Props, 12,000 shaft hp"

[dgaad]

Here are the stats for another DE to APD conversion :

DE-53 / APD-37 Charles Lawrence

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Charles Lawrence Class High-speed Transport: Laid down as a Buckley Class Destroyer Escort 1 August 1942 at Bethlehem-Hingham Shipyard, Hingham MA; Launched 16 February 1943; Commissioned USS Charles Lawrence (DE-53), 31 May 1943; Converted at New York to a Charles Lawrence Class High-speed Transport redesignated, (APD-37), 23 October 1944. Charles Lawrence was the lead ship in this class of APD conversions; Placed Out-of-Commission-in-Reserve 21 June 1946 at Green Cove Spring Fla; Laid up in the Altlantic Reserve Fleet, Floridia Group, Green Cove Springs; Struck from the Naval Register 1 September 1964; Final Disposition, sold for scrapping 31 January 1966.

Specifications: Displacement 1,400 t; Length 306' (oa); Beam 36' 10"; Draft 13' 6" (max); Speed 24 kts; Range 6,000 nautical miles at 12 kts; Complement 186; Troop Capacity 162; Boats 4 LCVP landing craft; Armament 1 5"/38 dual purpose gun mount, 3 twin 40mm gun mounts, 8 single 20mm gun mounts, 2 depth charge tracks; Propulsion, 2 GE Turbines, (turbo-electric drive), 2 boilers, 2 shafts, 12,000 Shaft horsepower.

[dgaad]

And another :

"DE-789 / APD-81 Tatum

--------------------------------------------------------------------------------

Crosley Class High-speed Transport: Laid down as a Buckley Class Destroyer Escort at Consolidated Steel Corp, Orange TX; Launched 7 August 1943; Commissioned USS Tatum (DE-789); Converted to a Crosley Class High-speed Transport redesignated (APD-81), 15 December 1944; Decommissioned (date unknown); Struck from the Naval Register 1 June 1960; Final Disposition, sold for scrapping 8 May 1961.

Specifications: Displacement 1,400 t; Length 306' (oa); Beam 37"; Draft 12' 7" (limiting); Speed 23.6 kts (trial); Range 6,000 nautical miles at 12 kts; Complement 12-15 Officers, 189-192 Enlisted; Troop Capacity 12 Officers, 150 Enlisted; Boats 4 LCVP landing craft; Troop Accoutrements, 6 1/4 ton trucks, 2 1 ton trucks, 4 ammunition carts, 4 pack howitzers, Storage, Ammunition 6,000 cu. ft., General Cargo 3,500 cu. ft., Gasoline 1,000 cu. ft., Armament 1 5"/38 dual purpose gun mount, 3 twin 40mm gun mounts, 6 single 20mm gun mounts, 2 depth charge tracks; Propulsion, 2 GE Turbines, (turbo-electric drive), 2 boilers, 2 shafts, Shaft horsepower 12,000. "

[Rich Dionne]

Good data dgaad,

We'll be taking another look at APD capacities, and this info will be helpful.

Regards,

Rich