Re: [TML] Destroyer tonnage... John Groth 16 Sep 2014 01:52 UTC
Grimmund wrote: <<snip>> > > Spitballing some numbers, I get about ~3000dtons for the Spruance: > > http://www.militaryfactory.com/ships/detail.asp?ship_id=USS-Spruance-DD963 > > gives dimensions of > > ength: 563ft (171.60m) > Beam: 55ft (16.76m) > Draught: 20ft (6.10m) > > and a crew of 393 officers and ratings. > > Side view here: > > http://www.the-blueprints.com/blueprints/ships/destroyers-us/7849/view/uss_dd_979_conolly__spruance_class_destroyer_/ > > > > meters, l*w*d > > Draught, 6 meters. If I understand correctly, this is waterline to > low point of keel: > > 172*17*6 > > Another 5 meters to the deck, above the waterline, estimated: > > 172*17*5 > > And the superstructure, estimated (this is a total SWAG on my part) > > 120*14*6 > > Check the photo here and add your own adjustments > http://upload.wikimedia.org/wikipedia/commons/e/e0/US_Navy_030321-N-6141B-006_The_Spruance_class_destroyer_USS_Briscoe_%28DD_977%29_underway.jpg > > > > totals a little over 42,000 cubic meters, divided by 14.25 is just > under 3000 traveller dtons. > > Thes, this treats the ship as a regular solid body rather than as a > streamlined body, and does not consider volume lost to streamlining. A number of years ago, I used the Akins FF&S2 spreadsheet to design the _Deyo_-class destroyer*, and ended up with a displacement of 3000 dTons. This matches the displacement of the _Midu Agashaam_-class destroyer, so this seems to be the size Imperial Navy planners expect for peacetime destroyers. I think I'll do some tweaks to the ship (I last worked on the design in January 2008 [file version "Deyo2b"]) and do a writeup. *Note that, _contra_ this Traveller wiki site's page on destroyers, http://wiki.travellerrpg.com/Destroyer AuricTech Shipyards equipped the _Deyo_-class with a spinal NPAW mount. Why? Because of some of the sweetest words a defense contractor can ever hear: "Cost-plus contract**" :-D Besides the obvious financial benefits that various cost-plus contract structures provide to AuricTech Shipyards, keep in mind also that FF&S2 doesn't simply provide a pre-built list of spinal-mount weapons. FF&S2 allows for spinal-mount weapons of any size, with the primary limiting factor being the length of the ship on which the spinal-mount weapon is to be installed. As such, AuricTech Shipyards has designed ships that mounted "spinal" NPAW weapons that were smaller than HG-based NPAW bay weapons (the advantage being that spinal-mount weapons are less vulnerable to damage when using Bruce Alan Macintosh's Military Combat System for T4 ships that are designed using the FF&S2 rules). **See http://en.wikipedia.org/wiki/Cost-plus_contract for details, with the stipulation that AuricTech Shipyards generally will only accept cost-plus-fixed-fee or cost-plus-award-fee contracts for Imperial forces. Private buyers who are willing to sign a cost-plus-percentage-of-costs contract will receive the most exquisite vessel their CrImp can buy (and our Sales and Finance Department is quite capable of determining how many CrImp a given buyer can afford).