#### snrdg121408

##### Mongoose

Breakaway hulls have popped up recently in two topics which has resulted in my not being sure of how the whole thing works.

I am using a PDF copy of HG 2e I downloaded on 09/01/2016.

Per HG 2e PDF page 12: "...This whole process consumes 2% of the combined hull tonnage for extra bulkheads and connections needed, and costs an additional MCr2 per ton consumed...."

1. The HG 2e example on page for a breakaway hull is based on a 1,000 ton hull that has a breakaway as a separate 400 ton vessel.

The extra bulkheads and connections tonnage requirement is 2% of the combined hull 1,000 ton hull which comes in at 20 tons and adds MCr40 to the basic hull cost of 1,000 x 50,000 = 50,000,000 for a total hull cost of MCr90. The 20 tons of extra bulkheads and connectors leaves 980 ton for the other components to be installed.

In the example the 400 ton section 20 ton MD has a Thrust of 5 and 600 ton section 66 ton MD has a Thrust of 9 installed. The combined 1,000 ton hull has an 86 ton MD which the example shows as having a Thrust of 8. Dividing the 86 ton MD by 1,000 results in a percentage of 8.6%. Looking at Step 2 Install Drives, page 14, Thrust Potential Table the 1,00 ton hull's 8.6% of hull tonnage falls between the MD Rating of 8 and 9. The rounding convention IIRC in MgT is to round down unless specified on how to round which means that the 1,000 ton hull's 86 ton MD has a Thrust of 8.

2. The 400 ton Fessor Cargo-Class Multipurpose Ship published by Jon Brazer Enterprises is designated as using a breakaway hull.

Following the HG 2e process the combined 400 ton hull has a cost of 400 x 50,000 = Cr20,000,000. The tonnage and cost of the extra bulkheads and connectors is 400 x 2% = 8 tons at a cost of 8 x Cr2,000,000 = Cr16,000,000.

The Fessor's record sheet has the Breakaway Hull as 196 tons with the extra bulkheads and connectors requiring 4 tons at a cost of Cr8,000,000. The 196 tons represents the total tonnage of the four 46-ton pods.

To determine hull tonnage used for the extra bulkheads and connectors 4 tons I divided 4 by 2% which equals 200 tons.

The Fessor designer appears to have split the 400 ton hull into two 200 ton sections. One of the 200 ton sections was further divided into four smaller sections. The 200 ton section that was split into four sections appears to have been used to determine the tonnage and cost of extra bulkheads and connectors.

What am I missing in the directions in how to create a breakaway hull?