Adding a cockpit locker for batteies

We are putting Itchen in a local heated boatshop over the winter to do overdue maintenance – strip & repaint the gunwales, replace and relocate the batteries, check out all the systems, etc, etc. I’d like to get the two 4D AGM’s and Group 37 AGM out of the lazarette and relocated forward and down. One thought is to retrofit Itchen with a port cockpit locker. This would regain lazarette space and add access to all that space in the engine room, plus provide a better location for the batteries – or at least one or two of them. There’s an earlier good discussion of various alternative locations here in the forum, but does anyone have any more recent experience with batteries, especially anything newly on the market?

I just discovered the BCC Construction Manual here on the website (Thanks!) and embedded deep within it is a very detailed two-page set of instructions from Roger Olson (thanks Roger!) on how to do it. I’d be interested to hear from anyone out there who’s actually done this and has anything to offer on how it went and what to watch out for?

I’d love to hear about this one too Scott.

Hi Scott, Don’t know if this helps any but we relocated our batts under the floor by removing the aftmost 15 gal. water tank. As a side note, we used Hydrocaps to keep gassing to an absolute minimum. Our house bank and starting batt were stored in the same compartment. I also added the cockpit locker lid, ours turns out to be starboard side. I can’t say enough about how handy it is and I had no special problems creating it. I did not follow Roger’s plan as I was unaware of it at the time(about 10 years ago)and so I don’t have as good a water drain system for the lid(working on that). I mounted it with Murray pull-apart hinges and it really is great. Not sure pics would help any but if you like, I can post a few. Cheers, Ray

I put my house batts under the sbd quarter berth (approx 300 ah) and the engine batt in the port aft locker low on the forward bulkhead. Cable runs are short which is nice, bo clutter cabin floor and works very well. I find however that we tend to store a lot of stuff on the sbd side which means more weight on that side. Simply speaking the sbd side is more accessible ( no table in the way) so one has to be careful the boat doesn’t lean to the sbd. AGMs were use which are fast to charge and sealed.

Hi Scott, on Sirena I added a hatch on the port side in the cockpit. It was realitivly easy since I was allready prepping for paint, so any grinding or body work made little difference. I cut the lid out of the deck matching some proportions of the lazzerrette lid. I then made a male mold for the gutter out of foam, matching the the angle of the lazzerrete gutter. I waxed and glassed the foam creating a three inch flange around the perimeter, I latter used this to glass the gutter in to place. I then de-cored around the edge of what is now the lid and filled with thickend epoxy and fiberglass.

Installation was pretty easy, it consisted of shapping the vertical face of the footwell to accept the fiberglass gutter, fiberglassing a horizontal piece spanning the the opening running fore and aft. This became the part that the front of the hatch rested on when closed. I then ground away the paint from the underside of the deck and fiberglased the gutter in to place. The rest was body work and paint. I think the whole opperation consumed around fifty hours.

I have been very happy with the way it turned out, the hatch allows so much better access to the engine room than through the cabin. I installed my batteries on a shelf that spans the hull in the engine room. I think some of the BCC’s have a fuel tank there. Good luck, the hatch makes a very functional addition to the the engine room.

Brooks Dollar
BCC Sirena hull# 51

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Scott, I found a picture of the finished locker.


I found a picture of the finished hatch.


pics 018.jpg

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Thanks Brooks,
That is a very lovely piece of work. Regarding your male foam mold of the lazarette gutter, was this a measure, eyeball and freehand carving task or did you do a foamed in place casting lifted from the original, and then adapt it as needed to the dimensions of the new locker cutout? Also, am interested in the locker itself – I see what looks like a tool and misc. gear shelf or tray in there. Since you mention the improved ease of access to the engine, is it entirely open to the engine space or is there some sort of removeable partion or liner or enclosure along the lines of Roger Olson’s suggestion? I suppose one might get by with stout netting to contain sailbags, life jackets, whatever.

I’ll want to do some serious measuring and test-fitting with a battery-sized foam-board mock-up, to see where the batteries might go with minimal hassle. I doubt I can get the entire kit of two 4ds and one Grp 37 in that space because Itchen has her fuel tank directly under the cockpit. Some combination of space under the quarterberth, a new shelf back of the galley buckhead under the new locker as suggested by Stewart, and perhaps a box under the companionway ladder ought to work.

Here’s a question for any engineering experts on the list (“Rod of Iduna”?). I wonder how big a difference in pitching moment would result from a shift of those three batteries from the lazarette to just aft of the galley bulkhead, or better, under the companionway ladder? Plus getting the anchor off the bowsprit and it and the chain snugged down in the head? When racing, a couple of seconds per mile makes all the difference, and surely worth the effort, but cruising? My instinct tells me that there should be a significant improvement in our tendency to hobbyhorse when bashing to windward in a square-wave chop, but perhaps this is reducible to numbers familiar to any naval architect? Topic for a new thread? Or to discuss over rum punch or beer at the Rogue Wave Reunion this weekend at the boatshow? I’ll be there, who else? Rod?


You have done a wonderful job of adding a cockpit locker! I had a cockpit locker installed on the port side of my BCC, and it looks amazingly similar to yours - the only difference being that mine was professionally built by a shipwright and cost me a small (actually, not that small) fortune! Mine has been configured as a propane locker, although it has lots of excess, unused space, which I know I am not supposed to use for any other purpose than that of a propane locker.

Great work!

Dioscouri (#064)


I did use the eyeball and measure method. I also used foam that was the same thickness as the lazzerette gutter, with a 3/8" round over bit for the concave.
There is a shelf with a drop down face mounted on cleats under the deck.It’s very handy for storing engine spares, oil etc.
The engine room is totally open giving me complete access to the engine and batteries. The only drawback is when you drop something it’s straight to the bilge.

Brooks Dollar
BCC Sirena #51

Ray, that is really interesting, had never thought of doing a
trade-off between the aft water tank and the batteries. On long
cruises we could add to the deckload of jerrycans, or add a small
backup tank somewhere else. Also I suppose it would put a premium on
having a robust automatic backup bilge pump and high water alarm to
minimize the chance of unanticipated high water in the bilge shorting
the batteries. On Itchen we had one heart stoppingly scary occasion
when a malfunctioning exhaust anti-siphon valve put water a couple of
inches above the cabin sole one day when we did a lot of motoring.
Hard to believe that little tube could supply so much water, an
unlikely event, but it did happen.

Photos, yes, always interested in photos of other BCC installations,
the cockpit locker addition is high on my list of upgrades, but do
want it to be water resistant and strongly hinged.
Thanks for the input,

2011/10/1 BCC Forums

Scott: Hi!

Itchen Wrote:

Here’s a question for any engineering experts on
the list (“Rod of Iduna”?). I wonder how big a
difference in pitching moment would result from a
shift of those three batteries from the lazarette
to just aft of the galley bulkhead, or better,
under the companionway ladder? Plus getting the
anchor off the bowsprit and it and the chain
snugged down in the head? When racing, a couple of
seconds per mile makes all the difference, and
surely worth the effort, but cruising?

I’m no engineering expert, just another BCC owner.

Six years back, to commemorate Zygote’s 5th launch day, I researched some of the questions you ask. And put the answers in Zygote’s Stowage & Ship’s Stores handbook (I’ve forgotten if I uploaded the Stowage handbook to this Forum. I remember that John Cole preserved some of Zygote’s handbooks in the BCC Maintenance Tips sub-forum and suspect they are still there).

I formulated a few principles for stowing, the first of which is:

"Rule 1: Keep the ends of the boat (bow, stern and masthead) light.

The formula by which pitching moment of inertia is calculated is:

Pitching moment of inertia = mass x (distance from CG)2

Moving a mass equal to just 1% of the displacement of the boat (ie 60 kg) from midships to the bow or the stern would increase the total resistance due to heave and pitch by about 1600%. This is especially important when beating to windward."

Zygote has the Sam L Morse Co. bookshelf to starboard. I mention that because Zygote’s Centre of Gravity (CG) is in the vertical plane about 14-17 cm aft of the central divider of the bookshelf (it’s not possible to be more precise, because the exact location of the CG changes with fuel, water, stores, and bodies etc).

In short, all you need do is measure the distance from the CG plane to where your batteries, anchor etc are stowed, square that distance, and multiply the result by the mass of the battery, anchor etc to calculate the contribution of that item to your pitching moment of inertia.

Doesn’t matter whether you measure distance in the foot size of a now-dead English king, cubits, or decimal fractions of a metre. You soon see that squaring a distance makes a big difference.



Yes Bil, your posting of 2005 has been retained, here:,3896,3896#msg-3896


Is there a Stowage Guide PDF anywhere on here? I’d be curious to see that. I find I’m always listing to port. The large storage areas are all on the port side. I struggle to put heavy things to starboard but it never works out well.

Hi Ben;

Unfortunately, no such document exists. Every vessel that came off the line was personalized in some way.


Side note John: I’ll be living in nearby Annapolis this winter aboard Elizabeth.