Hello to all,
We are almost finished with the theoretical averages and commonalities. We have confirmed many things, other things have gone without corroborationt but that is only until I get down South to bring the baby home. I decided she will be sailed home on her bottom for her make-over.
She will be sea trialed and driven hard for 1100nm! We're going to know if something is going to break!!
Today we calculated for storage, both fluid and solid, for consumable and perishable stores that must be provisioned. Check the offshore category definition for class A vessel and it will make a very important point, "must be self sufficient without expectation of any help for extended periods of time." What does that mean? Not much really. A circumnavigation can be coastal cruised without ever having to be more than 140nm from land, (I consider that distance offshore), if I had to sail to Caroline Island, so those provision requirements would be small, but who wants to spend the next 30 years circumnavigating by putting 217,000+ miles of coastline under the keel? That's almost the distance to our moon.
So, what measure do we use to provision? Do we stack, pack and wrap until our stores hang out of the hatches and hope that we have enough while we sleep on the rails? Yeah right. There are many assumptions that need to be made in order to calculate the right average.
For the Mac 36, I have decided that 2 on board for extended voyages is plenty, one male, one female, both of equal age 48, and the male weighing 250# and the female 160#. Their activity level is active to moderately active for a significant portion of the day. These assumptions are based on 3500 calories being equal to 1 pound of fat. However, not all calories are stored as fat, so I used only half.
Daily caloric requirements (BMR)
Male: 3422
Female: 2239
Total: 5660
Water consumption, equally complicated is based on the body fluids being the driving component because dehydration is related to body fluids. If one really needed to, one could survive on sea-water enemas or drink small quantities of salt water per day.
Daily Fluid Requirement:
Male: 0.61 Gal/day
Female: 0.33 Gal/day
Cooking: 0.33 Gal/day
Total: 1.27 Gal/day
Once minimum daily requirements have been calculated, the final components, time, speed and distance must be incorporated. For the Mac 36, the speed to length ratio is 1.9 which translates to 11 knots. The average speed calculated is shy of the 11 knots, but none expects to travel at such a V/L ratio consistently out on the ocean for reasons ranging from slowing down at night for better motion to sleep, to being becalmed or in light wind conditions, so, we can reduce her speed down to an average of 7.8 knots and then we'll consider ourselves becalmed for 8 hours per day as a safety factor, so we will average 7.8 knots for 16 hours a day.
Knowing speed and time, all that is left, is to establish distance. Assuming a temporary act of madness, a skipper would set a course to the one place on earth that is
the furthest point from anywhere on land. The pacific Pole of Inaccessibility. The name alone leaves me cold to the core. It is a point in the ocean that is 1451 nm from the nearest land. Doubling the distance for a return trip will be the distance used as the distance to travel without being able to provision for stores. The following results are calculated:
Days to travel a return trip: 23
Total Calories Required: 144,554
Stores Weight: 82.6#
Refrigerator Size: 21 Gallon/2.6 Cubic Feet
Total H2O Required: 29.5 Gallons
Fluid Weight: 246#
Water Tank Size: 2-15 Gal Tanks
Due to the weight penalty from carrying full water tanks, it would be an excellent idea to have a small water maker installed as part of the inventory. Empty tanks would substitute as flotation when not required and their dual purpose can be light ballast to increase stability during a blow offshore.
Electrical:Electrical is standard code and you may or may not use all of these.
Battery Cable: Safety Main Switch/ Red - 4 gauge
Mast Ground: White - 8 gauge
DC Supply to Switch Panel: Red - 10 gauge
Water Pumps: Red - 12 gauge
Cabin Lights: Blue - 16 gauge
Running Lights (Bow): White - 16 gauge
Running Lights (Stern)/Compass: White - 16 gauge
Steaming Lights: Green - 16 gauge
Anchor Light: Red - 16 gauge
Bilge Pump: Brown - 16 gauge
Bilge Float Switch: Tan 16 gauge
Sump Pump/Shower: Yellow - 16 gauge
All leads except for the float and the mast ground are paired with a black ground of equal gauge and connected to a common ground at the panel. The panel is then grounded to the plate, engine or rudder posts with 10 gauge black wire.
A nice, thick, 4 gauge length of wire can be attached directly to the compression beam beneath the mast so that it can be thrown overboard when running before a thunderstorm to create a straight path to ground (water) for the mast. When not needed, just retrieve it and store it to remove any drag. The same could be done outboard for the shrouds and stays just in case a stepped leader goes astray before connecting to the lightning rod. Anyone been in a lightning storm out at sea?
Ship to shore AC is standard code as well:
10/3 for the power cable
14/3 for outlets, lights etc.
12/3 for any lighting on the mast or at the bows.
All receptacles to be GFI
All wire should be stranded (not solid) and tinned with continuous uninterrupted runs with voltage drops no greater than 3% and all ends are terminated with crimp connectors. Forget fuses and upgrade the panel to circuit breakers. Cigarette sockets are discouraged.
Everything metallic on board should be grounded to each other and then to the most direct path to ground. Everything! Do not confuse electrical “grounding” with electrical “bonding” which is done to prevent electrolytic corrosion.
I had intentions to calculate loads for electronics, wind and solar generators, batteries inverters, etc, however, the required draw would be as different as there are skippers so those will be left to the skippers. Once I decide on my own set-up, I will calculate it and share it with the community. If it's any consolation regarding navigation, all you need is a sunrise and sunset because you will always hit land if you sail North or South or East and West when South of 60N and North of 60S so don't worry about getting lost.
Correction:
Block loads for a 430ft^2 Genoa
Running Rigging Block Loads
Deflection Genoa
30º 987#
45º 1443#
60º 1898#
75º 2316#
90º 2676#
105º 3018#
120º 3284#
135º 3511#
150º 3663#
160º 3739#
180º 3796#
Has it dawned on anyone yet that this effort will lead to a more in-depth study to establish what may be required to make her a category A offshore vessel as defined by certification agencies?
Enjoy the reading, the time has come to move on and prepare,
for us too. 
