Tuesday, November 9, 2010

Cooler Than Ollie



It is common knowledge that the Ollie box has been one of the great innovations in small boat sailing. It is a waterproof automatic timing and horn system for starting races. It can be programmed with up to three different sequences, selectable from inside the box. It has made life easier for many, many race committees and kept timing precise for the racers. It is unquestionably a great invention!

But as clever and useful as the Ollie box is, my good friend and fellow laser sailor, Eric, wondered if there might be a way to have an automated system that we could use in our informal racing where no race committee boat or race committee person is present. Could there be an alternative to rabbit starts that would help us all hone our time and distance judgment in starting? Could we just float an Ollie box and have one of the racers initiate the sequence?

Ollie boxes are expensive and fairly heavy, and one would sink like a stone if given the chance. It didn’t take much thought to realize that any flotation scheme risked losing the Ollie if something went wrong. It was particularly worrisome that it would not be our Ollie box at the bottom of the lake, it would be our Yacht club’s. Eric decided to start from scratch and develop another floating automated starting system that could be operated by a passing racer. Here is his description of his ingenious and low cost solution.

The device is built into a medium-sized picnic cooler which is about 10 inches wide so that it can be transported in a Laser cockpit. A 5 lb. barbell is used as an anchor attached with a 50 ft. line to a cleat on the forward end of the cooler. Excess line is wrapped around the cooler handle so the scope can be adjusted according to the water depth. The cover is secured and sealed by good old duct tape.


There are just two control switches, “Start” and “Abort,” which are doorbell buttons mounted on the aft end of the cooler. There is no separate power switch. The unit turns on when the start button is pressed, and automatically powers down at the end of the start sequence or when “Abort” is pressed. 

 A standard 3-minute dinghy starting sequence is used beginning with 5 short warning beeps and ending with a 5-second countdown to the long start blast. The short tones are ¼ second long with ¼ second spacing. Long tones are 1 second with ½ second spacing. The final start blast is 2 seconds long.

 
The sound source is a waterproof piezoelectric marine horn which has been likened to the sound of a dying duck. It is not terribly loud, but on the other hand, it does not destroy the eardrums of the sailor starting at the “boat” end of the line.

 



The electronics are housed in a small waterproof plastic box (in case the outer duct tape seal fails). The power is supplied by 8 D-cell batteries mounted to the floor of the cooler so they also serve as ballast along with two 4 lb barbells. The calculated battery capacity is about 2,400 starts, so battery life is really just limited by shelf life. Three empty 2 liter soft drink bottles are included in the enclosure for emergency flotation.

 


The electronics consist of a small microprocessor board (ARMite single board controller, Coridium Network Control Systems) with a few extra solid state components added to interface with the buttons and horn, along with some circuitry for the auto power-down. The software is just a small (about 170 line) program written in BASIC.

 

Overall, the system works pretty well, although I am sure there are improvements that could be made. Naturally, we have to use the honor system when it comes to being over early at the start. Maybe someone can come up with a paintball system to mark a boat that is OCS.

Yarg

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