Page 16 of 28

Updated may 2012: added information on the CF25 binoculars and acknowledgement & permission to use Frank Lagorio’s images of the binoculars.

Continuing from Part I , where I pointed out what goes where, here I have some images of the individual stands.

I collected nice images of all the bridge equipment components, trying to figure out what was what. I flipped through well over 15,000 images in online archives, probably missing a few here and there. I even bought a second-hand book because it contained a single good image of the air-defense officer’s sight. I put the best images in a CAD program and estimated the dimensions for each sight. Crew should be able to stand behind the sights at eye level, they should not be higher than the bulkheads they’re behind, and they should scale properly with each other, and so forth. I know that one Air-Lookout Sight is fitted to HMCS Haida, but that’s a bit out of the way for an actual measurement. Still, I ended up with some probable and consistent dimensions, or so I believe. At least most of these sights have one thing in common: the binoculars. Not the most accurate frame of reference, but still.

The binoculars are Barr & Stroud CF41 Admiralty Patterm 1900 night binoculars fitted with with built-in filters (yellow, green and polarizing). According to the Dock Museum, it measures LxBxH=235x170x90 mm, or about 0.67mm long at 1/350 scale, close enough to the 0.69-0.70mm I estimated from photographs (3-4% off). The bottom left binocular is actually the CF25 Admiralty Patterm  1949  with a 7×42 magnification type used primarily by observers of  the Fleet Air Arm, not the larger CF41 with a 7×50 magnification. The objectives are fitted with telescopic sun shades/spray shields, explaining the most obvious visual differences as seen bottom left. There’s quite a few people collecting them and a few of the better images of bridge equipment were found on binocular fora (none that mattered for HMS Hood, unfortunately). These images were using with permission from Frank Lagorio’s Flickr Account. You can pick up a pair on ebay from as little as 30 pounds; quite cheap as apparently many of these units suffer from prism separation. Note the yellow Admiralty arrows, designating acceptance into the navy. So, if you manage to build 1/350 bridge equipment and then manage to get 1/350 binoculars: they should have a pair of yellow dots.

This is the air-defense officer’s sight; quite bulky. . A chair is fitted to the pedestal of this director than apparently can be swung out of the way. It appears that the voice pipes can be mirrored for post side and starboard units (compare the left and bottom right image).

I used these images to make a simple CAD drawing. The chair can be seen at right at a near-ninety degree angle with the top of the unit. The center-bottom image is taken aboard HMS Hood (mirrored).

Here is the Air-Lookout Sight (Called Sky Lookout by the USN). It’s pretty well covered, that is,  now that I know what it looks like. The top is black with some lettering. Notice the aircraft recognition chart in the top left image of HMS Suffolk and the sunblocks in the lower-center part of the image. I noticed a sailor on the image of HMS Hood’s air-defense platform carrying this (one image up) and it appears to be standard issue for the lookouts.

Here’s the model interpretation, consisting of a few etched and CNC-lathed parts.

Now, in my previous post I mentioned a director for the UP launchers. However, in the Admiralty Fleet Order C.A.F.O. 2163.— 7-in., U.P. Mark I Equipments. Removal from Ships when replaced by Oerlikons (G/T.S.D./864/41 6-11/1941), a transcript of which is present on the official HMS Hood site clearly states that Air Look out sights pattern 12951 should be demanded from the nearest Naval Store Depot for each U.P. sight surrendered when these sights have been used in lieu of Air Look out Sights. So, are ALOs normally used as UP launcher sights?I do not see any unknown sight on HMS Prince of Wales’ bridge when fitted with the UP launchers, so I assume so.

Here’s the searchlight sight, with only one proper image scanned from Raven & Roberts British Battlecruisers of WWII book. This unit is clearly modeled by John Haynes; paying more attention to his work might have been a time saver.

and the CAD drawing including etched parts. I didn’t bother to add all etched parts, being nigh invisible when placed on the bridge.

A Perolus is fitted to the center of HMS Hood’s air-defense platform. The model hasn’t been completed yet. Note the sight at the bottom left image, far left.

Here are the models for the ADOs, ALOs and SLSs. Don’t worry, this is a large match. I had a few parts lathed by MASTER; I wanted to have the binoculars to be hollow and just couldn’t do it using my own lathe. As I needed 30+ parts, reproducibility became an issue. This is quite problematic when you have trouble with just one decent part. MASTER could actually get all (yes, all) the detail into these small parts and did an excellent job. They also milled the pedestals and the Vickers Valchorns (not shown). The parts were tricky to make, naturally, but the binoculars where quite easy; note I added the binoculars with and without the sun shades randomly. The chairs for the ALOs were first glued to a brass wire, then to an etched part and then to the pedestal. Clearly a part too many! It’s easy to get lost with the design of etched parts when they fill a 24″ monitor. I lost nearly no binoculars or chairs, but a lot of chair supports. The chairs for the ADO have yet to be added. No wire in the design here, fortunately.

A semaphore is not bridge equipment in the sense it’s a director or range finder, but is typically placed near the bridge with the other signalling equipment (lights, flag lockers). There was some discussion on a forum what the colors of the arms were (perhaps yellow/orange, as for the semaphore flags), but the website Royal Signals mentions that most signal arms were either white or black, or a mixture of both. […] On the ship there were often two types, the Mast head version with arms nine feet to twelve feet length, and the “bridge” mounted version […] with arms of six to eight feet length. I have my etched part at 5ft and they appear over-scale to me. Anyway, note the pattern in both colors and in the holes of the semaphore arms. These will be constructed when my model is being painted. The images are from random vessels with HMS Hood bottom left.

Next to the equipment known to be aboard HMS Hood, I have a few other close-ups I collected. These appear to be captains sights, indicative by captains near them (I think this makes sense).

There is supposed to be a target bearing indicator on the upper bridge wings of HMS Hood just below the air-defense platform and I assume it’s some sight; not another ADO. The left one certainly wouldn’t do , but I have no idea what type it could be. The right one would do; not visible in a photograph without the binoculars fitted.

Another nice set of sight variations, shown quite clearly. This is the Pelorus Sight.

This last one is the universal sight, a sketch of which can be found at the Historic Naval Ships Association. This unit was (amongst others) fitted to HMS Vanguard.

The Pompom director Mk I was described here. Not much was found for the Mk II and Mk III, but I have some images of the Mk IV to throw in so why not. The Mk IV was introduced in 1940 and can be seen aboard HMS Prince of Wales and HMS Kings George V (shown at right; note the absence of the radar aerials top right). Only the top-left image shows a Mk II/III. I have found not other photographs of the PPD Mk II/III. Fortunately I have the drawing from John Lambert Plans showing the unit in detail. A replacement of the model I have will be built later, with more etched parts and additional detail.

The three images shown above are all Mk IV pom-pom directors.  Note that these images show the director without the optical rangefinder which was removed in March 1944 from most units to reduce crew size.

One unit I mentioned in part I was the barrage director. I haven’t found a good image except one you can look up at the Australian War Memorial. The UK National Archives contain a pamphlet on the unit but the costs were a bit too high for this blog post.

Should you want to consult the Austrialian War Memorial (AWM) or Imperial War Museum (IWM), check out the following images:

AWM: 0356, 00313, 00627, 016988, 017502, 017637, 029536, 029538, 029562, 075411, 078120, 084640, 084641, 084642, 084644, 084645, 089369, 110179, 112191, 112341, 112355, 112360
IWM: 000872, 000874, 000876, 000878, 000888, 002873, 003651, 003883, 004218, 005667, 007696, 008432, 011001, 011213, 011803, 018039, 022617, 024208, 024326, 112355.

The models for HMS Hood’s funnels were already completed a few years ago and were of the few remaining parts of the first generation. The walkway at the center of the funnel was solid styrene, not a nice new etched walkway and the railings weren’t done so nice. So, I decided to have new parts for the funnel in the etch set for the walkway and the one-bar railing and start all over. Little did I know that these were the parts with the highest failure rate of any sub project I did so far.

This is the only one good shot (known to me) of the funnel interior, taking from high up in the bridge structure. It would have been wonderful if the sailor who took the image would have taken one of the funnel closer to the bridge so that the interior would be fully visible, because almost no other information is to be found. You have to interpret the image careful to distinguish between the railing of the walkway and the vertical and horizontal supporting bars and stays. The first thing to note is that there a walkway going around at the edge (so that the crew can deploy and fix a canvas cover) and a walkway in the ships length direction, but there is no walkway across the funnel in beam direction. Second, note that the (only) walkway across the funnel ends a bit higher at the far than the walkway around the funnel. As the funnel cage is curved, it would make sense for the across walkway to correct for this curvature and be a bit higher so the crew can pull the canvas cover over the grid. These covers are rarely used and are seen mainly when ships are being built or when mothballed

Few drawings of the funnel interiors exist at all but I managed to find two in Anatomy of the Ship (AOTS) Dreadnought and Belfast. This image is from the former source, by John Roberts. Even here it is mentioned that the exact layout is not known and is based on contemporary design. I decided to “create” HMS Hood’s funnels based on this information. You can notice a few things in this wonderful drawing. First, a ladder is seen from deep within the funnel going toward the walkway. The crew had to access the funnel from the upper deck. Now, if you look at the top image, you’ll notice that there’s an opening in the railing of the walkway. Hence, an opening for a ladder must be present for HMS Hood’s funnel as well. So, the shape of the walkway is distinctly different for the walkway as sketched by Roberts in AOTS HMS Hood.

Second, a large number of internal funnel stays are visible. The position of the stays remains unknown, except the two in the top image. Two vertical supports from the funnel cage down to the walkway seem to be at the same position. However, only two supports sound a bit low so I added two additional rows. I cheated a bit, as you cannot see them in the top image, so I decided to let those additional two stays start a row lower down. The stays end above the division plates at the bottom of the funnel. I didn’t add an etched walkway for this funnel interior, as I forgot about it and the previous version of the funnel ended one deck higher on the model so it couldn’t be placed. So, I’ve hacked that part away to show the division plates. Anyway, the design for the educated-guess funnel interior is now done.

A hollow funnel is one thing, but snugly fitting the etched part is something else, so I experimented a bit. I had a mould made from the dimensions of the etched walkway and wrapped it with plastic plate and put it in the oven. I spent a lot of time playing around with the plate thickness, the dimensions to get a good part, the temperature and the heating time. I ended up at 150 degrees (C) for two and a half minutes. The result is a thin 0.25mm plate with the correct shape. A second plate was wrapped around the first one and they were glued together. I had to add a few markers so that the plates were glued in the same position when they were heated, of they might deform the funnel a bit.

The result is a heat-treated funnel that fits the etched part like a glove! (the part in the middle is the antenna for the Type 273 radar and is not part of the funnel).

Adding the stays was the next experiment. I make a small ring from two additional layers of heat-treated plates and drilled in the funnel with a 0.2mm drill. Brass rod was inserted, glued with CA and later trimmed to size. I made several attempts, as a small misalignment of a row of holes showed up only too easily. The rod was added with the funnel on the mould to have something to hold the funnel with, lowering the mould with each successive row.

The result looks quite good, though I had to be careful not to exert too much force bending the brass rod which doesn’t bend back. Corrections can be made, but the results were not always too precise for my taste. So, for my second series (reason for doing so stated below), I tried using fishing wire. A series of channels was carved in the outer plate and the wire was weaved around the funnel. This did solve the problem of a brass wire not being able to stand tension, replaced by a wire that couldn’t take compression. So, I had to use some force pulling the wire taut, and I tore a hole through one of the funnels at the last pass (of course). Not so useful either. Still, all the channels and adding some pretension did work out quite well, so I went back to brass wire.

So I kept the idea for the channels and added some tension by pulling the wire and bending it downwards before trimming it to size. A third layer of styrene was added to bring the funnel to its required thickness before adding the exterior detail: next in line were the rivets on the outside of the funnel.

I already added some rivets to the tops of the main gun turret and decided to continue that technique here. I visited a repair shop for antique clocks and they gave me a collection of very fine gears. I made the tool you see in the picture above.

The plate width required for the funnel was first measured carefully using test plates and divided in strips. Using a table, the caliper, and a ruler, I rolled in line after line of rivet detail.

The result is a nice plate, a bit over-scale, but the effect should be worth it.

Adding the plate proved to be quite troublesome, as you cannot use normal glue as that will melt the thin plate and using superglue leaves very little room for error. Here can see the test fits of the plates (I had only half the rivets on the left funnel, so it was replaced).

The problem with the first set of funnels was that I accidentally removed a bit of rivet detail. The split between the plate ends is cleverly hidden behind steam pipes, but still, people may want to go searching for errors for the funnels just to see if there’s a plate line and spot the ugly area. I tried to repair this part by cutting out a part of the riveted sheet and add some replacement sheet, making matters much worse! These funnels were trashed, something I learned to regret later on, as these funnels were really a lot of work.

So here are the last versions of the funnels. I didn’t manage to have the horizontal bolt lines align properly for both funnels. Gluing was quite tricky, as the plate needs to be aligned properly and the smallest deviation will show up. Work to fast and you can make an error. Work to slow and the glue may form lumps that will show up immediately and you need to carve off the plating and clean the funnel (another hour or two). The split is filled and looks reasonably fine on a close-up and it’s tricky not to damage the lines of bolts on either side of the gap. Do note that the spacing between rivet lines along the split matches the distance between other lines quite well (hurray for planning ahead). Fortunately the double steam pipes, one set per funnel both over the split, will run over the horizontal lines.

Here you can see a collection of the failures.