Bilges, Bulkheads & Valves

Description of Bilges & 

Air and Watertight Compartments

The Challenge 2000 Class boats have six potentially water tight sections - some of which are also potentially air tight. Starting from the bow and moving aft in order these are:
  • The bow crush chamber. As originally built has no holes in it other than an air tight metal plate for access held in by some very beefy bolts, siliconed sealed through deck bolts for hardware and for two valves at the base of the inverted pryamid. The valves allow draining this section to the one aft.

    Some folks are putting in draining chain lockers here. We elected to leave this unbreached and put the anchor windlass into the sail locker.
  • The sail locker. In our boat, this houses the chain for both anchors, the anchor chain rodes and windlass. It is not water tight due to the windlass. There is a large custom Lewmar hatch to allow deck egress and the removal of sails from the locker. We keep our outboard here as well. This compartment has a water tight bulkhead within which is an Hercules door. Two bilge level valves allow drainage of this chamber into the one aft.
  • The Forward Cabin Compartment. This area contains the black water tank (in terms of USCG, there really is no grey water tank on these boats) and the two heads. The sea cocks for this plumbing are found in the mid line just before the door into the sail locker. This bilge has two valves that allow water to be moved into the main bilge compartment aft but also has, in Ironbarque, am automatic bilge pump.
  • The main compartment has in its bilges:
    • The four fuel tanks with their associated piping for filling and taking deisel from them
    • The four water tanks with their associated piping to allow water from the dock (via the starboard head) or from the water maker.
    • The bilge manifold (see below)
    • The main salt water intake for the engine.
    • An automatic bilge pump.
  • There are three aft compartments that are NOT separate:
    • The Port Aft Cabin
    • The Main Engine Room
    • The Starboard Aft Cabin

      At the level of the bilges, these compartments are separated by steel.  However all three bilges are linked about the level of the midline lower bunks that lie on either side of the engine room compartment and the swinging fire access ports on either side of the engine room doors. The walls above this level are ply. There is free progress between the Port Aft and Stanrboard Aft cabins at the communications console above the level of the bilges. There are two Hercules water tight doors that allow these three compartments to be kept separate from the main compartment provided that the access hatch into the engine room, found behind the main companionway ladder, is water tight. On our boat, at the time of purchase, this was most definitely NOT the case.

      The main watertight pass through between the Main Bilges and the Engine Room Bilge is located on the foreward transverse bulkhead of the engine room at the foot of the companionway.

      There are two sets of two through bulkhead 1" pipes that are unused; one set between the Port Aft Bilge and the Main Bilge, and, one set between the Starboard Aft Bilge and the Main Bilge.  These are capped off.  They were apparently there from a failed first attempt at providing non-siphoning vents to the deisel tanks. We have used them as pass throughs by uncapping them, passing through the wires we wanted to pass and then filling them with self expanding foarm.
  • The "Lazarette". The final compartment is the stern.  It is not really a "lazarette" (but what else to call it - ?stern crush chamber?). It has two Lewmar hatches into the bulkhead plus two valves found in the lower shelf space of the built in cupboards at the back of the aft cabin.   The deck plate takes multiple bolts and some wire pass throughs. The dry exhaust from both the generator and the main engine pass through this bulkhead. There two drainage valves allow water to be moved from the "lazarette" bilge to the aft bilges forward. These are found, in our vessel, in the left and righ lowest storage cubicles at the back of the aft cabins (you really have to get down in there to see them). There are sufficient unsealed breaches of this area, in Ironbarque, made to allow wiring to pass up to the instrumentation that this area cannot be regarded as being air tight. It appeared to remain water tight during the one strong gale we have been through.

All the bliges hoses (Stb Aft, Port Aft, Main Engine, Main and Forward) come to one bilge manifold. The drawing for this is below.

In MANUAL bilge mode, the person pumping the bilge (aka the Bilge Rat) opens the outlet to the MAIN PUMP and the inlet to the manifold from the bilge that is to be pumped. All other bilges should be kept closed otherwise you will either suck air from the open and empty bilge and/or allow flooding between bilges.  The Bilge Rat has the option of pumping from the deck pump. The process is the same except that you open this outlet and close the main manual pump outlet.  

As built, there is an electrical pump WITHOUT a float switch in the main bilge that can be operated from the main electric switch panel.

The outlet from the Main Manual Pump, the manual Deck Pump and the independent outflow from the electrical pump meet in a four way SS strong box located behind the panneling in the OilSkin Locker. The three inputs share one output. There is a valve on the outlet. The location of the outlet through hull is to the starboard side just above water line.

As It Was
As It is
Pump Detail
The links above will take you to a VSD (Visio) derived file that shows the before and after schematic of the bilge arrangments for Ironbarque. In case you were wondering, "Why change what worked so well for so long for the Challenge Races?". There are two reasons:
  1. When she was unattended at a mooring in the Lymington river, Ironbarque's propeller was left untethered. The current was apparently sufficient to spin the propeller.  The rather old seal on the shaft leaked.  The engine room flooded to the point where water entered the engine. We had a rather expensive head job on our hands.  Arguements can be made about batteries that deplete and wiring that burns out. We decided that, having solar/wind trickle chargers as we will, it made sense to have at least one other line of defense other than our presence on board to defend the integrity of the vessel against such "accidents".

  2. We will be sailing as a family.  Although my 15 year old can happily keep the manual pump going, my 12 year old tires and my 10 year old and 5 year old are not strong enough.  All of them are smart enough to go to the panel and hit the appropriate (and obviously arranged and labelled) switch.

  3. Nothing is perfect. The pumps have such a long run that they need to be either well immersed or well primed. Additionally, if you are using the hand pump, the force on the checkvalves will stop the automatic pumps operating as the manual pump force into the common manifold exceeds the individual automatic pump forces so that the check valve is kept closed.