The Ship Model Forum

I printed a trial A frame today which is drying prior to curing. Looks good so far but actually fitting it to the ship will check the exact size. I am still wondering about moving it over center. If I were guessing I would opine a jury rig davit swung over the port side to pull it outwards. I'll look for a anything that looks like a stowed davit. Forward on the Port side there is such a davit at the rail but way to far forward for this usage. Certainly the port side boom could be swung outboard and maybe effect this evolution.

There has been legislation introduced in the Senate to make the Federal Workers who have been vaccinated go back to work (ending paid vacation). As a modeler perhaps the folks will go back to NARA and I could obtain the BOGP for ARL 13 I requested. (12 wasn't available). Because of the great modifications to Sphinx I have to rely on my dad's photos for Poseidon's wartime configuration currently. At least being original wartime photo prints some have decent detail.

Cheers: Tom

Pass one at the portside A Frame Derrick.

Tom

In the spirit of info comes to light after you have fashioned an item, I had done the double winch on the main deck, port side, a decent enough effort. Looked like a pretty authentic winch, but then a photo of the winch in question shows up. So off to the races again. I printed the new winch and it looks pretty good, still lacking any details on the far side, but that�s life, as with the dark side of the moon, up until recently, guesswork.

I took a closeup with the eye pad and was preparing to post when the power went out. Windstorms often blow trees down on the power lines. Maybe later!

Cheers. Tom

Port Fwd Double Winch. I was able to find a decent photo of this on Navsource. Sailor standing in front obscured some detail and far side is unknown, but fairly good guestimation.
Padeye/shackle/turnbuckle/link/Pelican Hook "train". Larger one is for ARL12 in 1:120, smaller one for 1:200 warships.

Tom

Head on view, this evening. All this stuff just sitting in place. With the flat bottom and shallow draft, she will even roll on a tabletop!

This photo taken using a technique called "photo stacking" to achieve sufficient depth of field using a Canon 100 mm Macro lens. A series of photos are taken with a set of focal points along the length of the hull and then combined in Photoshop.

Tom

As seen passing under the Golden Gate Bridge, off to Pearl and Ulithi.

Eye-Phone photo

Tom

Tom,

Most impressive, is all I can say!! You're really doing a bang up job on the individual items - I may have to try a jug of the Rapid Black resin as the detail is really coming thru on all of your parts. I esp. like the winches, davits, cargo handling gear - very intricate work!!!

Hank

Thank you Hank! I find building and installing the bits and pieces a fairly enjoyable part of the construction. I tend to avoid parts I don't like, for example the hull is not yet painted, not one of my favorite tasks. However I do need to complete this before I begin adding the superstructure parts which are easily destroyed during hull handling.

A ways down the pike, base for display is a question. Docking blocks are a good system, but because of the 1:50 slope of the bottom do not display the ship in a level attitude, even though it was dry-docked in this manner.

I printed padeyes with shackles (free to rotate) but may try print some smaller ones. There was a pretty god photo of the winch control box for the double winch and I printed several of these, but I have to investigate as to whether this winch had only one, or two? The other winches also had such boxes on stands, but I am not sure they were identical to this one.

Tom

Tom,

Now that I see the "A" boom/derrick in place I understand your earlier question about how it was swung out over the side.

Perhaps it was never positioned straight up, but always left tilted outboard so gravity would pull it out/down. If it was raised vertically, what prevented it from swinging inboard?

Did the ship have boat booms or other booms along the side of the hull? If so they could be swung out and vangs for the "A" derrick could be run through blocks on the boom. (But how did they run out the boat booms?)

****

This brings up the question what the "A" derrick was used for? Positioned along the port side as it was it could not be used to hoist things onto the deck unless they were small enough to pass thorough the opening in the "A". I wouldn't want to try that at sea when the ship was rolling and pitching!

The two winches were the topping winch on the starboard side was used to control the vertical angle of the derrick - lower it over the side and raise it. The winch midships was the burtoning winch that raised and lowered the load being moved.

There is another possible use for the "A" derrick. It could be used for highlining objects between ships or the ship and shore. For this the objects would not be brought aboard, but would be lowered onto boats or barges alongside.

Phil:

Photos clearly show the A derrick inclined inboard at several degrees. My WAG as to it's employment was to hoist large craft out of the water and then a lighter was slipped underneath, this used as a working surface. It was common to see them underway with a barge alongside. Other possibilities? Lower one of the LCVp's and use it to pull the boom over center? It may be there is provision for a riggable davit or boom. There is one such permanent davit, but this is too far forward for such usage and may be used in conjunction with the portside boat boom. A PT boat or an LCM could be handled in this way onto a barge. I have seen quite a few LSM's nested on the port side where the derrick could be used to hoist either engine out for overhaul or repair.

Forward, in the area of the sloped forecastle there were two parallel awarthships beams on which boats could be placed (I haven't built these yet). Additionally the bow doors could be opened and the ramp dropped to allow LVT's to drive aboard for onboard work. There is a photo on Navsource showing Poseidon at Okinawa in this configuration. Probably a little cooler for the repair crews as well.

Of course the simple system might be to latch on to whatever you were going to lift and take a strain, pulling the boom over center?

Tom

Photo at San Diego taken from starboard bridge wing, USS Poseidon

Tom,

On the OK City we had a small boom that swung outboard to position the vang for the boat boom. Even with only the small angle provided by this boom the longer boat boom could be started swinging out from the hull. Once it started moving it could be positioned using the two vangs. A small portable davit could be used to generate the pull to swing the "A" derrick outboard.

After the "A" derrick was swung inboard, as shown in your photo, what stopped it from falling down onto the deck?

Phil

Phil:

Not obvious in this photo, but the derrick was hinged on the main deck and rested against the O1 level. Not rigged in this photo, but two heavy cables were stretched across the deck from the top and fastened to padeyes near the winch and took up the strain on the deployed derrick.

I haven't identified the two large canvass covered objects just inboard of the derrick, my guess either air compressors or diesel generator units. I have seen these on several ships of the class. Guessing compressors?

Tom

ARL 3 under shipyard fit. An early ARL, and later ships differed somewhat but you can see how the A Frame derrick is hinged at main deck level and nestles into the extension of the O1 level.

Tom

As to boat booms, I have seen them rigged either port or starboard just aft of the front of the deckhouse. What I haven't seen in any photos is where they are stored as they don't seem to be permanently affixed to the ships hull. I suppose this is due to frequently having vessels come alongside. Main or O1 level storage would be fairly obvious as these are not small items. Because of the numerous outboard stanchions stowage on the main deck outboard of the deckhouse would not be feasible and photos don't show this.

Hmmmm Tom

Steps forward and backwards, and forward. As I had mentioned I have been dragging my feet on painting the hull. One of the prior tasks was adding the ribbing alongside of the hull. I had used a non porous beaders cord, which being smooth, I thought would work well. However it failed to adhere well to the hull, as I had relied on the auto body primer to help keep it in place. When I was about 12 years old I made a model of this ship and the thread I used for this still adheres so, going backwards in materials, I am re applying these using thread, anchoring the stern end with a little CA, then streaming PVA along the length with my fingers and laying it on the hull with a little tape to hold it. So far so good!

Always something new to learn/relearn!

Harrumph! Tom

Looking at the A Derrick photo above, there is an arm just above the O1 level that extends inboard. The photos so far are not clear enough to illuminate it's function, but it could be used somehow to pull or push the arm outboard enough to be over center? These A derricks were sometimes found around the shipyard on barges but I never paid much attention to them. I would be surprised if this installation was some new and unusual invention of marine technology, though it does baffle me that all five cargo winches are different. At least on the APA there were only two, one spool and two spool versions, though essentially the same in design parameters. No "Winch, Standard, USN, Medium" for instance.

Small mysteries. Tom

Tom,

Looking over the photo, I've edited it with a couple notations - just what I'm seeing from it. How it is raised/lowered I can't say - the controlling winch for that is out of the picture. But, it does appear that there are 2 I-beams laid athwartships on either base leg of the derrick that appear to be separate (as noted) from the derrick. Perhaps a conversation with you dad (if possible) would answer these questions (?).

A most interesting question, to say the least.

Hank

Hank:

Poseidon had two single spool winches. One controlled the raising and lowering of the A frame and the other the hoisting block. Yes the deck supports are separate and nestle the A frame in-between, the frame hinged at the base, main deck level. I am guessing that an initial tug on whatever the load is was used to pull the frame over center. That would be the simple system. I do have a couple of closeup photos of this area from dad's album, taken from the port bridge wing.

In further mystery there were two very large support beams, awarthships in the bow area, just aft of the 40 mm quad. I have variously seen 40' motor launches stowed here. Guessing that this was an area to store a craft being worked on. I have a photo of a 36' LCVP being hoisted in this area by the forward booms. What I don't know is if these beams could pivot and exactly how they were supported, though they are supported off the deck by several feet. I do have a closeup that shows the end of a beam so I can closely estimate the size and construction. Guess I'll have to waddle through all the Navsource photos again.

Getting close to shooting the hull color, may have to make up another paint batch as I did when i got to this point on the APA. As I mix my own colors, this is time consuming, but it is possible to get a good match.

Tom

It was common to see various cranes and such on barges around shipyards. I suspect this is just another harbor crane, but this time the "barge" was seaworthy.

Following up on what Tom said, it appears that a diagonal I beam rose from the forward transverse I beam on deck, leading to the A frame, and possibly another beam coming down from it as a support or rest for the A frame on that side.

On the aft transverse I beam it looks like there was a platform above the deck that extended over to the A frame where the ladder steps start up the side of the A frame I beam. You can see a ladder from the deck rising to this platform.

The problem with the idea that the hoisting block (burtoning block) was used to pull the A frame outboard is that the block is massive. What was used to pull it outboard?

Because the A frame is almost vertical it wouldn't take much of a push to tilt it overboard. I suspect the Chief Bosun just walked over and gave it a sound kick. No one argues with the ship's bosun.

Phil