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Consigli di Rod Stephens: IMPIANTI
scafo | cabina | impianti | ponte | armamento | vele

1. Correct Scupper Guards: All too often the scuppers are either dangerously restricted by the use of a plate with a few small round holes, or perhaps totally unprotected. The logical arrangement is the use of a lightweight cross, which prevents large objects, which could stop the scuppers, from getting in and creates no measurable restrictions.

2. Cockpit Seat Scuppering: Inadequate drainage of cockpit seats, which results in carrying undesirable quantities of water inside the lee coaming, which is particularly dangerous if there are related cockpit scat hatches. Even when the cockpit is at deck level, it is no cure to cut through the coaming, as this merely lets water in from the windward deck. There should be large capacity scuppers, which can lead athwartships outboard with a very minimum of pitch, as they only come into effect when the boat is heeled in the direction of the scupper. If the seat area can drain into a T-section of the cockpit well, this is the best solution, as it provides almost unlimited capacity.

3. Coaming Locker Drains: A great many boats have a useful and convenient locker in the wide type of coaming, which is associated with the modern glass construction. Again, there is no short cut to draining such lockers. You really need an internal drain, with some filling, so that everything in the locker tends to drain toward this scupper. Again, simply cutting holes to the outside or into the cockpit seat area will let in as much water as it lets out.

4. Pump Intake Screens: There are many excellent diaphragm pumps, as exemplified by Edson, Hendcrson, or Whale; and these pumps have a pretty good capability of handling expected impurities, but this in no way helps the fact that anything that gets into the pump intake may block the pump hose before it ever gets to the pump itself, so that no matter how invulnerable the pump is, as demonstrated at the Boat Show, it is most important that there be a cross guard, or similar, to prevent large objects from getting into the intake piping; but without reducing the important maximum capacity of the pump.

5. Pump Discharge Routeing: Layout of bilge pump discharge piping is a critical detail. There are a great many boats which appear to leak in heavy weather; and, in many cases, some of this water is coming in through the pump system, as the pump valves themselves are not completely foolproof, particularly in view of the fact that a certain amount of miscellaneous solids can and will go out through the pump system, and these may temporarily hold pump valves open. The only sure cure is to have the pipe looped up high, close to the deck, and as near the centerline as is feasible; and, where possible, pump discharges should be above the waterline, which in turn will prevent any tendency to siphon in; and will permit you to observe how well the pump is operating.

6. Deck Bilge Pump Location: These are all too often located inside of one of the cockpit seat lockers, which is absolutely the last thing that you might be able to open in an emergency in heavy weather at sea. Pumps must be so located that they can be used without admitting any water into the boat; and also so they can be cleaned or repaired; again, without letting water in. The location should be near the centerline, near the lazarette hatch; but arranged ideally so they can be pumped through a tight gland in the after end of the cockpit well, is perhaps ideal; and, hopefully, the location should be so the helmsman can use it, so that in short-handed sailing it is possible to be sure that the bilges are dry, without having to go below to check. The second pump should be located below deck, so that in extreme heavy weather it is possible to pump without going on deck; and, in an emergency, both pumps can be used at the same time. Ideally, they should be the same type to minimize the requirement for spare parts; (In extreme emergency, one pump can be cannibalised at a time when both are out of operation, and it may permit you to come up with one that is still useable.)

7. Sink Locations: Galley sinks and toilet washbasins should not be located in a position where they can temporarily go below the waterline under extreme heel. It is not good enough to think that somebody is going to remember to close some particular valve, quite apart from the fact that with such valves closed the sink or washbasin could not be used. In former times a washbasin well off the centerline could be drained into a toilet bowl; but, with restrictions on toilet discharges, this becomes less desirable. Sinks and washbasins should be located near the centerline, and high enough so they do not go below the waterline; and so that nobody has to remember. In cases where the sink or basin is poorly located, there is a temporary expedient, a spring loaded gate valve can be installed, that is kept shut with the spring; but can be held open to permit emptying.

8. Toilet Bowl Height: Toilets should be located with the edge of the bowl four to six inches above the plane of flotation so that if the intake valve should fail, there would be protection from flooding the boat.

9. Toilet Intake and Discharge: There are too many instances where the toilet seawater intake is placed either so high that it comes out of water in rough weather, or perhaps heeled in one direction; and often it is located too near the outlet, so that an undesirable amount of re-circulation occurs when the boat is stationary. In general, the intake should be low down, and reasonably near the centerline; and the outlet higher up, and further aft.

10. Toilet Overboard Discharge: The toilet discharge line should be looped well above the waterline, and the loop should be kept inboard, so that it still performs its protective function, even when the boat is heeled.

11. Tank Sounding: All tanks, both water and fuel, should have provision for sounding; and appropriately marked sticks should be furnished.

12. Tank Clearance: There should be provision for cleaning all tanks, with the exception of gasoline tanks, where any removable access plate would provide an undesirable possibility for leakage.

13. Tank Vents: Tank vents seldom get the thought they deserve. Fresh water tanks should never be vented on deck; as this just provides a possibility of salt water contamination. The vents should be located reasonably near the centerline; and, if possible, arranged so they discharge into a sink or washbasin that drains overboard, and there should be a separate vent for each tank. It is then possible to make very sure that each tank is completely filled by continuing to take water, until the vent does overflow. On the other hand, fuel tanks should invariably be vented to the deck; and in a position where the normal flow of air would not carry smells or vapors from the vent back into the cabin.

14. Through Hull Fittings: A well thought out arrangement of all through-hull openings can add to the safety, and ensure proper operation, as, for example, toilet intake seacock must be in a point where it will be well below the waterline, under all conditions. The same for the engine cooling water intake. Overboard drainage from sinks and washbasins should be straight, if possible, to facilitate cleaning, and frequently a toilet intake can be tee'd to the same seacock that is used for the basin drain. Cockpit scuppers, where possible, should be above the waterline; this not only decreasing the possibility of leaking, but also the location above the waterline means that any fuel vapor in the cockpit will drain away. It has already been mentioned that exhaust should be above the waterline, even when going full speed; and that pump discharges should be above the waterline, where they are visible. Finally, seacocks should be located so that they are reasonably easy to service, and to operate; and, in all cases, they should be clearly marked in the full open and the full shut positions.

15. Fresh Water Check Valves: One of the most universal shortcomings in the fresh water system is failure to install a high-grade check valve in the lowest part of the supply line leading to any galley or sink pumps. Such a check valve keeps water in the line, and ensures satisfactory operation of the pumps and eliminates many unnecessary strokes otherwise required to get air out of the line.

Rod Stephens,
Problem Areas, in: Yachting World Annual, 1973, pagg. 43 e segg.

 
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