Foundation Findings #42

Setting the Standard

The effect of the lanyard kill-switch is immediate, meaning that the instant you pull the kill-switch key out the engine will shut-down. With the wireless systems we expected there to be a delay between the transmitter sending the signal to the base unit and the engine shut-down. So to more accurately measure the time it took to for the engine to cut we established a baseline standard with the lanyards.

Lanyard Kill-Switches (Click for Link to Manufacturer)	Ease of Installation	Installation Diagrams & Directions	Time from Engine Kill to "rest" •	Detachment Force (Pull Angle)			Lanyard Length (stretched)	Price
Lanyard Kill-Switches (Click for Link to Manufacturer)	Ease of Installation	Installation Diagrams & Directions	Time from Engine Kill to "rest" •	High	Mid	Low	Lanyard Length (stretched)	Price
Units Tested	1=Hard 5=Easy	Yes/No	Seconds	(back)	(side)	(down)	inches
Sea Dog - Universal Kill Switch	4	No	6.11	2lbs 4oz	4lbs 2oz	3lbs 1oz	64.5	$13.99
Cole Hersee - Emergency Cut-Off Switch	3	No	6.11	1lb 4oz	3lbs	1lb	53.5	$22.99
Sea Choice - Kill Switch	4	No	6.11	1lb 7oz	4lbs 11oz	3lbs 11oz	64.5	$27.59
Sierra - Emergency Cut-Off Switch	4	Yes	6.11	5lbs 12oz	6lbs 7oz	6lbs 1oz	53.5	$19.99
Universal Key Sets
KwikTek Universal Key Set (on the Sea Choice kill-switch)	n/a	No	6.11	17lbs	15lbs 3oz	15lbs 6oz	64.5	$10.95
KwikTek Universal Key Set for PWC (on the Sea Choice kill-switch)	n/a	No	6.11	7lb 2oz	1lb 9oz	1lb 10oz	48.5	$14.99
• Measured as time between when sensor is dropped in the water and when boat came to "rest" - "rest" being defined as when the boat slows enough for its wake to slap against the stern

With nearly ideal conditions, few waves and no breeze, we set out to test the lanyard kill-switches. In our 22’ center-console with a single 200hp gas-powered engine, we took off on a plane at 35mph and pulled the kill-switch key out as we passed an anchored buoy we had set. We timed 6.11 seconds between when we pulled the kill-switch and when the boat came to ‘rest’. We measured a distance of 125 feet between the first buoy and our ‘rest’ point. For the purposes of this test we defined the term ‘rest’ as the point at which the boat slowed enough for its wake to come back and slap against the stern. This will, of course, vary from one boat to the next as well as with differing conditions. We were lucky to have a steadily calm day throughout all of our testing – of course that made it incredibly hot and humid in the middle of the day on the Chesapeake Bay, but we survived.

The decision to use this concept of ‘rest’ as our basis for timing stemmed from the assumption that we wouldn’t be able to accurately determine when the engine cut with each of the wireless devices. We could assume it would cut when the alarm sounded but that proved to be untrue with at least one of the systems.