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Bridge Superstructure, part III

February 8, 2009 / efoeth

The parts of the bridge and fore bridge were already quite finished, until John Roberts posted the sketch below on the official HMS Hood site.

This layout, with a split level, is different from the single (extended) level in the Anatomy of the Ship series (Drawing E3/5, p86) . Two windshields are visible at the right image (arrows) that support the split-level layout. Note that the right windshield is a bit broader. I suppose this part of the shield can be swung to the side to allow access from the lower platform. The UP-launchers on the boat deck can be similarly accesses by opening the splinter shields. Note the railing at the sides of the air-defense platform (top of the image) below the canvas-wrapped equipment (inside of the arrows). These railings run wider than the roof of the fore bridge and forward position of the air-defense platform. If you look closely, you can see a ladder between the railing and the closed wind shield. The new drawing by Roberts seems to work out quite well with the few photographs of this part of HMS Hood.

The left side of the image shows the admiral’s bridge. The right side is a top view of the new layout. The width of the wind shields is taken from head-on photograph.

As the bridge part was already completed, it needed to be modified for the new layout. The left image shows the inserts I made for the lower half of the split level. This level is quite low, too low for any person to be standing around it. I made this part solid. I have no references whatsoever, but at least it gives the model some support. The right image shows the upper half of the split level. A part with an opening for a ladder according to the old layout was first truncated, then the platform was extended. Note that the bridge part consists of two parts that fit tightly so that the entire bridge can be painted more easily.

A series of voice pipes runs from the air-defense platform. I don’t know where they end up in the platform, nor do I know where the go except for the ones on the photographs. Note the railing in the top left image, indicating the platform on either side of the air-defense position is as shown top right; with a small 45-degree angle. The bottom part of the image shows the voice pipes in a forward shot and the model. Seems to be a good fit. The damage to the part being dropped to the floor is already repaired! These voice pipes took about 3 hours to add.

The entire bridge and fore bridge as a dry fit. From the photographs it is clear the voice pipes of the air-defense platform run backward, but I can’t see where the are going. All spotting-top voice pipes run toward the tripod, so I decided that all these voice pipes run down under the aft half of the split level toward the tripod legs. The only problem is that they are now partly blocking the door to the compass platform, but I guess they are a bit overscale. Note the opening for a ladder where the split level can be accessed from the admiral’s bridge and the voice pipes at the inside of the air-defense position. This area will be filled with air lookout equipment later to add some much needed detail!

Vents II

January 18, 2009 / efoeth

For some reason I avoided beginning to build all the mushroom vents of HMS Hood. There are many sizes and shapes and they are both numerous and small. I took the basic measurements from “Anatomy of the Ship: HMS Hood”, drawing I1: Fittings. I brought the total number of different mushroom vents down to about four and tried to classify all mushroom vents on the drawings and photographs. I decided on Large (2.4mm or 0.095″), Medium Large (2.0mm or 0.08″), Medium Small (1.22mm or 0.048″, a US punch size), and Small (0.8mm or 0.0315″). I tried to do a head count and came up with 13 large, 18 medium large, 32 medium small, and 31 small; 94 vents in total. As these parts are small I might loose them during handling and as I probably missed a few on the drawings or pictures, I had to make a nice supply of parts.

The largest vents are visible here, cut from tube. I added a disk to all rings so that the support of all mushroom vents has the same height; I now need to cut the support to length on the model, paint it, and then add the mushroom vent. This way I know what the height will be before painting the entire ship and I do not have to get the height correct of each vent to what is visible on the photographs after painting . After this disk was placed, a small disk was glued on top of the vent as detail. None of the vents on the photographs have any more detail such as a hand wheel. Too bad, would have looked nice. The grille of the vent is simulated by an etched part bent into shape and set with superglue. I only had tubes for the largest vents, the two medium sized vents were made from rod with the center punched out as explained here. This was some work with many casualties due to off-center punching, dropping to the floor, misalignment and more dropping to the floor.

I started with the largest vents which I found to be small to begin with, and worked my way down. The smallest vents were really a challenge. I started by cutting up rod in batches of ten. They had their centers punched out by the ten-fold. I decided the smallest vents can probably be put into place prior to painting with little risk showing their white undersides or can be placed on the painted model. So, I put the rod in place. I first slid the rod in (bottom left), dipped the tip into superglue and slid the ring into place. The bottom right shows the result prior to sanding.

These are all the vents; 20 large, 34 medium large, 40 medium small and 58 small, 152 total. At least, 152 are left and dozens more are scattered around in the hobby room. Perhaps casting a few would have been possible, but I didn’t look forward to the prospect of casting several batches of tiny parts with a high failure rate.

Making rings with a Punch & Die set, part II

December 31, 2008 / efoeth

I posted a small tip how to make rings with the punch and die set (here). I made a small refinement that allows for the punching out of holes from rod or disks. For this, I used the Waldron Sub Miniature Punch & Die set (any set will do). I would advice people who want to do scratchbuilding to buy both Waldron sets (or make their own).

1) Take a styrene strip with a hole so that it can swivel around the pin of the set. The strip should be as thin as or thinner than the working material.
2) Place the strip in the set and punch out three holes. One hole is for the working disk, the other two for positioning. Do not remove the punches until all three have been used.
3) We now have a simple template that can be repositioned using the two outer punch holes.
4) Now, drill the center hole to the exact diameter of the working material. I also added to holes at the far ends of the strip and added two disks with the same height as the disk.

5) Insert the disk into the center hole and press it so that it positioned tightly.
6) Position the styrene strip and fix it using the outer punches for the exact location
7) Gently punch out the center of the disk and remove all punches. Swivel the strip outwards and remove the ring.
8) Make many!

The advantage of this technique is that it works for all combinations of inner (depending on the punch & die set) and outer diameters. You only need to have the exact drill size ready, which is much easier than making sub punches on a lathe as with my previous tip.

Update added 18-01-09

A small refinement was added to this tip. I let the styrene strip swivel around the largest punch. The second punch is taken to set the strip into position with the third punch for the actual punching. The pic shows I use an array of holes. Top left shows the positioning with the smallest punch. At top right the holes are drilled in where the rings can be positioned. Bottom left shows a series of 10 disks in place with the result shown at bottom right. From the close-up is visible that not all rings are concentrically, so you need to throw away some of them. I also marked which side of the mould is up, as reversing it results in all rings being punched off-center.

Octuple pompoms, part I

December 29, 2008 / efoeth

HMS Hood has three older octuple 2 pounders, or pompoms for short. I already made a few of these models a few years back based on the drawing L/0/66 of John Lambert Plans. I even included a few etched parts.

This is the first model on the band stand on the boat deck. Looks quite good and has sufficient detail. But, two things were constantly bothering me. One, I’d found a good source of tubing from Cammet Ltd with the right size of tubing for the barrel and the cooling sleeve while this one has solid rod, and two, the newer commercial etch sets have a nicer floor representations and even ammo belts. Even though the commercial etch sets have lots of errors (lots), I feel I can do much better.

So, I spent a few days going over the drawing by John Lambert, the Vickers Photographic Archive, and some assorted pictures, and made new parts in Autocad for etching. This will be quite an interesting folding exercise! A bit of random detail will be added to the model but it’s mainly etched parts. A second larger etch is in the works which I hope to have finished soon.