Saunders-Roe Seaplane Tender
Another post of a model I completed some time ago. This was a departure for me in terms of scale as this is built to 1:12th scale and was intended to be a working model, though in the end I didn't fit the motor.
I completed it around 2010 and it languished on a shelf looking a bit rough. In 2015, I re-worked it and these pictures are of it as it is today. The boat was entered into the 2016 Model Engineering Exhibition where it was awarded a Silver medal.
Below are the notes I prepared for the exhibition:
Overview
I found drawings of this boat in a book written by Uffa Fox, first published in 1937 titled Racing Cruising and Design and as Uffa himself says, what appealed to me was the hull shape which I quote as I couldn’t write it better:
“The flare off forward, throwing the sea away from her decks, is washed out amidships, where her side is plumb, while aft the tumblehome takes any heavy look away from her transom, and besides this cuts down on the wind suction from the stern by that much”
Studying the drawings (reproduced below) I could see that it needed to be a largish model, so I chose 1:12 scale, a departure from my normal 1:48th scale.
Seaplane tenders were designed to transfer passengers and crew from the shore to seaplanes. This tender, designed, built and operated by Saunders (later Saunders Roe) was used in the Solent between 1920 and WW2, I have not been able to find out and operational history other that which Uffa describes. He says it operated for 25 years (before 1937) but as Saunders only entered the seaplane business in 1920, I have dated it from then.
The tender dimensions were:
Length overall: 36ft
Beam: 6ft 6in
Draught: 2ft 5in
Displacement: 2.43 tons
Max Speed: 15 knots
Sources
As can be seen from the drawings, there is very little true detail and searching the internet, the only photograph I could find is reproduced as the thumb-nail to this post. Again, this shows very little detail, but I did find photographs of a similar seaplane tender, fully restored and for sale, plus drawings of many components in a copy of Davey & Co’s fittings catalogue from 1961 (most fittings had not changed since WW1).
The model was built using the following sources:
The plan in Uffa’s book
Various illustrations of boat and ship fittings from Davy’s catalogue
Some additional detail from the photographs found on the internet
Conjecture
Originally, the model was intended as a working model and still contains a motor, battery pack and servo, however, I have completed it as a static model, supported on an acrylic stand so the lines can be seen unencumbered and surrounded by the inter-war seaplanes Saunders-Roe produced.
A similar fast tender of the same period shown below
Construction notes
The hull was a major challenge and one of the reasons I wanted to build the model.
There is no parallel section, it changes continually. Because if this, it is planked with double layer of diagonally laid 1/32nd balsa strips, bending across the grain, glued to thin open frames to produce a strong, very light hull. The hull was then coated, inside and out, with clear epoxy to both strengthen the balsa and render it water-tight. It has a single bulkhead at the front of the cockpit for added strength as I guess you would see in full scale practice. A 1/16th inch ply sub-deck was then attached (to deck beams forward) to further reinforce the construction and the deck planked in lime-wood with calking from black card. The passenger area was then also planked on the inside and the crew seat built up to act as a storage place for the battery box (see picture below).
Finally, the framing for the passenger deck and rear seat (which all comes out to allow access to the rudder servo) was built up.
The gratings were home-made to be the right size, being such a prominent aspect of the passenger area, as was the engineering plate in the crew space (etching glued to aluminium). The column throttle was turned and capped with an etched ring.
The silencer and exhaust are modelled as shown on the drawing, the engine would have been water cooled via the exhaust and so I added a water intake on the port side below the water line and a heat shield where the passengers sit. The fittings were all scratch-built from brass.
I added the lifebuoy as it seemed strange she could have operated without one and the Saunders-Roe logo because I wanted it represented on the model.
The model is displayed in a Perspex mount to show the lines and on a clear base containing pictures of Saunders Roe flying boats of the interwar period.
I love this anchor, all scratch made from bits of brass, the flukes fold and the cross bar slides to it fully folds per full scale practice. It was based on this illustration from Davy’s ship fittings catalogue
These leather cushions are made from brown fimo, can't remember how many failed attempts it took to get them right
Underneath the seat is the silencer and exhaust, with a grill to protect the passenger's legs
The engine room bulkhead with fire extinguisher, great graphic made by Nigel at Flightline Graphics. The rev counter image came from an illustration I found on line. The green floor-mounted wheel is actually the speed control and forward/reverse.
You can see the lifebuoy rope well in this shot, made on my rope-walk. True rope (as opposed to thread or string) lays down correctly.
The steering wheel was etched (4 pieces), is works with a servo controlling the bowden cables. The calking on the deck planking is done with black card stuck to the lime-wood strip edge before installation
The hand operated light works if a battery is installed. Checker plate is diagonal mesh soldered to copper plate, centre section lifts out
Beautiful arrangement of the rudder and propeller bushing, the exhaust is in the background.
Finally, safe from enquiring fingers in its oak framed glass case.
What makes this model one of my favourites is the fact that it is so clean and simple, no fussy detail interferes with the lines allowing the viewer to enjoy the grace of the design and the patina of the wood. It is aging well.
