Arternoon Neville, If you're happy with the way they work in the Richardson then leave the covers off. If you want to experiment fit covers around the transducer but not touching it, analogous to speaker cabinets😉 For simplicity it can be square/cubic in form, with the back about 1cm from the back of the transducer. Glue some thin, fairly dense foam rubber in the back. With luck this will concentrate more noise outside where you want it. The flyboys cut a hole in the fuselage and cover it with gauze, just like a Hi-Fi box. NOT very practicable for a boat😲 Cheers, Doug 😎
Continuing with the cabin, trying to keep it light in weight. The sides and inner former's made up, started on the front windscreen's. Forgot the procedure about cutting the windows and then fitting the veneer, fitted the veneer and had to cut out the windows veneer and 3mm ply all glued up. Once the apertures were marked out, purposely drilled though from the veneer side just trying to avoid any splitting of the veneer, it worked. Fitted the front screens and reinforced the framework with 5 min epoxy, a quick sand down and all was well. Next item was the roof, as i wanted a light as possible upper works decided on .8mm ply, it looked and felt a little fragile, but once the Titebond glue was applyed all held down with elastic bands, also using 3 strips of 3/8" x 1/8" Obechie longitudinally down the top of the cabin roof to help stop ant edge "Barrelling" at formers. Regards Muddy.
Knowing v little about radio waves and antenna construction, I'm happy to accept your line. My assessment was purely on trying to identify the teardrop's purpose and matching its shape to similar units in RAF use. It was usual for ships then - merchant and military - to have a DF system and it just seems logical for a vessel with search and rescue responsibilities to have one! Positioning of nav lights was subject to complex rules in the 1950s and still is! One thing, that I don't think has changed, is that the for'd steaming light must be mounted a significant height above the red/greenside lights. The cabin roof would not be enough! Interesting that we both have similar lengths of experience associated with similar naval vessels. Maybe we crossed paths sometime gone!!
Hi Astromorg, Hmm! Your assessment throws up some interesting questions! 1 If the 'teardrop' is a DF antenna what frequency band was it intended to detect? It's way too small to contain the multiple antenna elements necessary to detect, and determine the angle of incidence, of any frequency in common use at that time. I've also never seen a microwave waveguide that shape. If DF I would expect a rotating loop antenna in that era. 2 It's my conviction that the tear drop on the Vickers Wellington is a streamlined VHF antenna. Or just possibly a radar detector much later in the 'grand ruckus'. 3 Why would a Fireboat need a DF set anyway? 4 Some photos clearly show a forward facing lens (white disc) in the teardrop. 5 Such boats when tied up to a mooring buoy instead of the dock would require a 360° visible light. Hence mast-top is the favourite mounting place. 6 Visible angle is primarily a question of the lamp and lens construction and not necessarily the mounting position. 7 A stern light providing the 'fill in all round' is a contradiction of the purpose of running lights which are so constructed and mounted as to help the observer to determine which way the vessel is moving. Forward and aft lights visible 180°? red and green 90°. Which combination you can see helps indicate which way the vessel is moving; towards or away from you. Conversely the single anchor light should be visible from any angle. It can be yellow to distinguish it from a running light. Current regulations also recommend the use of deck lights while at anchor. 8 I agree re position halfway up the mast for the forward running light, BUT, as the masts on these vessels were often folded down the permanently fixed forward running light on the cabin roof would make sense. But then, that's only my opinion! And what do I know?😲 I only worked in communication engineering for 45 years, the last 32 of 'em in Integrated Naval Communication Systems, on all types of vessels from Fast Patrol Boats through FACs, OPVs, corvettes, frigates, conventional subs and up to Escort Aircraft Carrier. Cheers, Doug 😎
I would suggest that the light at the top of the mast, while appearing to show all round may actually be masked internally to give the necessary visible angle of 112.5 degs either side of dead ahead. The stern light in the transom will give the 135 deg angle to fill in all round. The teardrop-like unit on the for'd cabin roof looks more like the style of radio direction finder used by the RAF on their aircraft - the one on top of a Wellington bomber is particularly obvious. A useful fitting for an RAF crash boat? Positioned as it is it could not give the required 225 deg beam if it was a steaming light. Normal position for a steaming light would be halfway up the mast at about the yard position, but aside from a small unlabelled bracket on the original masthead drawing, I can find no evidence of a light ever being photo'd there. Combination masthead lights for steaming or anchor are common enough today. Perhaps that was how it was?
Hi Canabus, #382 may well have been what you say! But this model has obviously been built as a THORNYCROFT 43ft RANGE SAFETY LAUNCH. The cabin structure and fittings are totally different. For me the 'give-aways' were the three side windows and the foreward bulge on the cabin. I had wondered about the number on the model from the outset. http://www.rafboats.co.uk/rsl43.html Pics show one example FoC #1640. On the above url you can see several more. Pic 7 is a MK1 40 foot Firefloat #55. Last 3 pics are 40foot MK1 Seaplane Tenders, #377 in a sad n sorry state😲 but apparently about to undergo restoration? Cheers, Doug 😎 PS: Attached also a pic of Firefloat #90, a MK1A. She was converted to a Seaplane Tender #467 in November 1949. FF91 was converted to ST382 in Feb 1950.
Upperworks, this launch has a long cabin and a well deck ( Gin Parlour ).. Sides were traced out and cut from 1.5mm ply, internal formers are 3mm ply, spacers and struts Obechie, the cabin front is formed with Balsa which will be covered in 1.5mm ply, all the external faces have been veneered in Mahogany, except the roof which will be probable a piece of ply. The old favourite 1 inch ring saw came into play again for the cutting out of the windows. Applied the veneer after cutting out the windows, have found this easier and it tends not to split and crack the veneer, so one has to recut the window openings but its a very quick and easy job if you use a 1/2 inch drum sander in something like a Dremel hobby type drill. I,m afraid we have the oposite of Rain stopped play , its Sun stopped play at the moment.. You may notice the "Old Batteries" and cans, used as weights to hold down / compress the veneer, also the Jig saw, bolted to a piece of ply and then clamped into the B&D Workmate, I aint got room for a bandsaw which i would love, so this lash up has done me proud for a few years. Regards Muddy....
The ‘Range Safety Launch’…………. Intro. I am now the owner of this boat. Wooden, good hull lines and hull paint work but needing to be finished. I am told that it looks like it started life as a kit, but has had considerable modification to at least the above deck layout and detail. Advice is that it could be a rather simplified Range Safety Launch, but maybe I can use a little ‘artistic licence’ and just make it look interesting and capable. There are two main reasons for sharing this project. 1. I will undoubtedly need guidance 2. Maybe some of the information will assist others The hull is 44 inches ( 112cm ) long and 14 inches (36cm ) wide, it has two brushed MFA Torpedo 800 motors………. and weighs in currently at 15 lbs 4ozs (6.91 kgs). It is large enough for me to be able to work on reasonably comfortably and apart from the cabin/upper deck areas to be ‘improved’, I aim to introduce sound, lighting, active radar sweep, search light, together with maybe a deck hoist and water /fire monitor appliance. At my age it is difficult to tell the difference between wishful thinking and dementing…… However, the prime aim is to try and achieve at least some of this whilst having the boat usable during the current ‘season’. There is so much knowledge, good will and help available on this site that even before I touched a thing, information came pouring in. If anyone feels like making a contribution then please just ‘pile in’. Have ordered some parts so next time should have something to show. NPJ.
Next query I will be fitting a 360 deg white mast light, and is there also at the front centre of the fore cabin a small white navigation light. I think it is shown in the black and white photo of the 93 at mooring.