Well, we finally got the combination of no rain. bright skies and light winds, so it was off to give the latest model its first shake down run.
A photograph of a launch used by the Pilots at the Soo Locks in the North American Great Lakes had been laying in my "got to build sometime" files for too long. It looked like it would make an attractive model and also give me the chance to try out a new idea or two.
The first idea was to try and build it as a simple, shallow draught and flat bottomed hull. The original plan was to use a flush-decked hull but the real boats have a lower recessed area in the stern. I couldn't really ignore this feature so the simple idea was compromised a little although an easy way to make it was found. Likewise, the superstructure block was first built as a simplified shape but when completed and placed on the model it looked awful. Luckily it was only a little harder to make something closer to the original.
To keep the weight down, the hull was made from balsa sheets with card/balsa for the detachable block. Further weight saving was made by using a RE 365 motor and eight rechargeable cells. I figured that a light and shallow draught model wouldn't need that much in the way of power. The planned RC items and the likely materials were weighed, adding a bit for glue and paint and it gave me a target model weight of around 24 ounces.
I then fell into the trap of comparing photographs of the real thing and then looking at the model. It seemed rather bare and so started adding extra details. The final model weight came out at 28 ounces, a little more than planned but still gave me a draught of about 1/2 inch which I had aimed for.
Sailing was something of an anticlimax, it behaved perfectly. Immediate response to the rudder with turning circle diameters down to around 7 feet (2 m). It was even steerable when moving astern. Top speed was about 3 ft/sec ( 1 m/s) which allowing for the models scale of something like 1/30, corresponds to the full size doing about 10 knots, a reasonable figure?
Overall, designing and building the model was an interesting challenge. A few new useful ideas discovered when it came to detailing the model. The shallow draught idea worked out OK but, as earlier tests in the garden pond had shown, it could be easily blown downwind if not under power. Not perhaps a model for those who park their creations in the water and then turn around to chat to fellow modelers..?
I always take two models when sailing to maximize the fun and just in case.... This time it was the Type 23 Frigate, what a contrast as it goes way over scale speed with full throttle, unless the real ones can do 50 knots?
Glynn Guest
