Towing and Trailering Flashcards
The two forces that affect towing?
Static and Dynamic
The layer of water immediately in contact with the hull while it moves and creates drag?
Frictional resistance
Created by the design of the hull and how it reacts to motion thorough the water?
Form Drag
The rapid, extreme increase in tension on the towline, which transfers through the tow rig and fittings to both vessels?
Shock load
A dip in the towline caused by its weight?
Catenary
How much more stretch would another 50’ of towline give to act as a shock-load absorber?
5’-20’
Ideal towing course should be ___ to ___ degrees off either side of dead ahead or dead astern?
30-45 degrees
Some nylon cordage can stretch up to additional ___ percent of its length before parting?
40
What are most towlines usually made of?
Double braided nylon
The length of a towline can be as long as?
900 ft
The bitter end of towline is attached to the tow reel by what?
Small stuff
When putting new cordage in service as a towline, what should be done to both ends?
Eye splice
Can tow reels with mechanical advantage or electric motors be used to retrieve a towline under tension?
No
Unless slipping the towline in an emergency, at least how many turns of towline should be kept on the reel?
4
Damage to line caused by overheating or over-stretching?
Fusing
Wire rope should be used to tow what type of vessels?
Large vessels or Steel huls
A _____ is used to reduce wear and chafing at the towline end?
Pendant
What angle should the legs of a bridle be to reduce the amount of tension?
Less than 30 degrees
A length of light line used to carry a larger line or hawser between vessels?
Messenger
A heaving line equipped with a rubber ball or monkeys fist should be at least how long?
75 ft
A buoyant synthetic line attached to a ring buoy or float, deployed upstream or upwind?
Float line
Designed to equalize the load on an eye of a line and provide max chafing protection?
Thimble
This device is deployed at the stern of the towed vessel to help control the vessel’s motions?
Drogue
How long is the drogue towline?
200 ft of 2” double braid
The drogue line is marked every?
50 ft
Before starting the approach of a vessel in need of tow, a ________ sould be established?
Danger zone
When what is the formula for calculating max safe tow speed?
S = 1.34 x Lw and Ss = S - (.1 x S)
S = max tow speed
Ss = max safe tow speed
Lw = square root of length at waterline
The effect of current on vessel navigation at 12-30 knots is greater than or less than the effect while towing at 6-8 knots?
Less
Current flowing directly against the steered course?
Head current
Current flowing in the same direction as the course steered?
Tail current
A current that is flowing for either side, across the intended track?
Cross current
At a towing speed of 7 knots, a 2 knot cross current will require a heading offset of over ____?
15 degress
The weight of the vehicle with a full load of fuel, with no passengers or cargo?
Base curb weight (BCW)
The base curb-weighted plus the weight of passengers and cargo?
Gross vehicle weight (GCW)
The maximum allowable weight of the fully loaded vehicle?
Gross vehicle weight rating (GVWR)
The weight of the towing vehicle and fully loaded trailer, including passenger and cargo?
Gross combination weight (GCW)
The trailor tongue weight should be how many percent of the total trailer weight?
10 -15%
Without a special permit, what is the widest trailered boat allowable on most state roads?
8 ft
How are safety chains attached to the tow vehicle?
Criss-crossed
What is the max speed when towing any trailer?
55 mph
For every 10 mph of speed, how many car lengths of distance should you have between you the vehicle ahead of you?
2 vehicle lengths
