S Class Questions

[ancient46]

I've been working on setting the sub draft to make the game's subs look like as the official Navy photographs. However I have run into a problem with the S class. I can find lots of excellent examples of how the S-18 and S-42 types sit in the water but they do not match the sub modeled in the game. Many are much much different.

If I lower the sub to match almost all of the pictures I have and set the waterline at the bottom of the anchor the rear is too high. Here is a sketch of the 1944 S-20 to illustrate the problem. http://www.navsource.org/archives/08/0812507.jpg I am assuming the line drawn through the boat on the external view is the designed waterline.

If anyone can point me to a reference that pictures the S boat modeled in the game I would greatly appreciate it.

On a side note the S-20 was commanded by John Phillip Cromwell from 1936-1937. A SH4 attack method by Rockin Robbins and Nisgeis was named for this CMoH winner.

[LukeFF]

The hull shape of the S class is based on the 1920s'-30s style of the hull, before the boats were modernized. A draft of 5.3 meters will put it where it needs to be historically correct while on the surface.

[ancient46]

I wish they had modeled an S class as one we would have seen in the war. I wish they had used a boat like the S 30 type.

Most of the information I found was that the safety Mod done before the war started included the marker buoys but the model does not have them, only the hatch. I found a design sketch of one of the later 18 types and I can work from that. I was going to leave out the S boats since I couldn't match it with any picture I had found. For me it is not worth changing the draft unless I can demonstrate a historical basis for the change.

[LukeFF]

I wish they had modeled an S class as one we would have seen in the war. I wish they had used a boat like the S 30 type.

Most of the information I found was that the safety Mod done before the war started included the marker buoys but the model does not have them, only the hatch. I found a design sketch of one of the later 18 types and I can work from that. I was going to leave out the S boats since I couldn't match it with any picture I had found. For me it is not worth changing the draft unless I can demonstrate a historical basis for the change.

Not to mention the hull type we have is for the S-18 group of boats. The hull for the S-42 had a noticeably different shape both near the stern and forward of the conning tower.

The interior model...ugh, don't even get me started on that abomination... :rotfl:

[DaveyJ576]

The drawings by Jim Christley that you have referenced on Navsource are quite accurate. The waterline shown on the drawings is probably a light load waterline. That is the waterline with no fuel, fresh water, stores, or weapons on board. The actual full load waterline would have been about 12-14 inches deeper. The torpedo tubes would not have been visible and the rudder would have been just below the surface, out of sight. It was also not uncommon for the boats to be slightly trimmed by the stern, leaving the boat with a slight up angle when at rest.

The safety mods done during the 1920's cut away part of the superstructure "skeg" that ran down from the end of the main deck to the rudder. This was done to allow the installation of an escape hatch in the motor room. However, the normal surface trim of these boats resulted in this escape hatch being underwater at all times.

Take a look at this picture:

http://www.navsource.org/archives/08/0813105.jpg

The safety mods also had rescue buoys installed at the aft end of the superstructure were the skeg was cut away. However, not all of the boats got these buoys right away. Some were not installed until 1941.

There was no significant difference in the hull shape of the later S-42 group as opposed to the earlier boats. The S-42 group was 6 feet longer and the conning tower fairwater was shaped differently (to accomodate a gun access trunk at the forward end), but other than that the hull shape was the same. What you might have been seeing were before and after photos of the skeg modification.

Some of the boats received extensive wartime modifications and this radically changed the visual outline. See photo of S-47 below:

http://www.navsource.org/archives/08/0815807.jpg

It is amazing that the waterline did not radically change as new guns, radar, sonars, and A/C were added.

[ancient46]

Well the problem I am having is finding the boat used for the games model. The best view I found was the S-18 taken in after 1943 http://www.navsource.org/archives/08/0812307.jpg. If I set the boat so that the water line matches the photo the rear of the boat with part of the screws is out of the water. I am trying to match screen shots in sh4 with the historical records. I want to make our screen shots look as if it were actually a color photograph taken during WW2. It was relatively easy until I hit the S class, then things got complicated.

[DaveyJ576]

Well, the only thing that comes to mind is that the computer model was cobbled together incorrectly. At this point it is the only thing that makes sense.

To be really historically accurate, you would need three major models:

1. The S-18 through 41 pre-war configuration

2. The S-42 through 47 pre-war configuration

3. The S-42 through 47 wartime modifications

In addition as the S-boats had radar added in 1943 this would need to be reflected in the models. A few of the boats (S-35, 38, and 41) had some rebuilds of the after superstructure done, but we may be getting beyond the capabilities of the game at this point.

[LukeFF]

In addition as the S-boats had radar added in 1943 this would need to be reflected in the models. A few of the boats (S-35, 38, and 41) had some rebuilds of the after superstructure done, but we may be getting beyond the capabilities of the game at this point.
Were the radar displays situated in the conning tower? Looking at the pics at your site and at Navsource, I just don't see how they could have fit in the control room, and furthermore, I've never seen a pic of radar display installed in an S boat.

[DaveyJ576]

Information regarding the location of the radar displays in the S-boats is fragmentary. My feeling is that they would have been installed in the conning tower, but I can't confirm this. The S-boat conning tower was a vertical cylinder and was quite small. It could only fit about 3 men. The original design had one periscope in the ct, but this was removed in the 1920's.

Outline drawings of the modernized S-boats show the SJ radar mast penetrating the ct so logic would indicate that the display was likely there. However, most of the attack functions and equipment (including both periscopes) had been moved down to the control room. You are right, though in that the control room was also very small and adding the radar display there might not have been possible with all the other gear that was present.

So I'll go with a conning tower installation until shown other wise.

I did find out one other thing. The aft rescue marker buoys that had been added as part of the safety mods during the 1920's were removed once the war started. It was felt that they were more of a liability as they could come loose during a depth charging. For this reason, on the fleet boats the buoys were also removed or welded down so they wouldn't release. It wasn't until after the war that these buoys were reinstalled. Your updated computer model of the S-boats should therefore not have the buoys in place.