General HydroStatics
Ship Stability Software
Command of the Week
(New or interesting aspects of GHS that you may not know about)


Do boats have feelings? Some say they do.

In the countless times our faithful "Fishing Vessel" FV.GF has been made an example of, we never considered how she must feel not having a bow thruster. Back when she was designed, bow thrusters were not so prevalent as they are today, and no thought was given to the possibility that she might want one. Unfortunately, the proper location for the tunnel puts it squarely through a transverse bulkhead. It is barely feasible to put it there by tilting the drive motor into the engine room space, but the tunnel impinges on not only the engine room but the forepeak tank and two double bottom tanks as well.

Nevertheless we undertook the project:

variable (len) Lth=38.5f, Vth=3.5, Dth=1.5
enter pm
 create hull\bowthrust.c
  cylinder (20) {Lth}, 0, {Vth},  {Lth}, 10, {Vth},  {Dth}
  fit hull
 macro tunnel
  create %1\tunnel
   shape hull\bowthrust.c
   fit %1
 .tunnel "forepeak.c"
 .tunnel "db0.s"
 .tunnel "db0.p"
 .tunnel "engrm.c"
 quit pm
 solve weight, lcg
 THRUST "Bow Thruster", 0.5, {Lth}, 0, {Vth}
 hmmt report

Note that the THRUST increased the heel angle by only a fraction of a degree, so it was hardly worth doing for stability assessment purposes. But FV looks much better with her new thruster, and we trust she feels better too.

Questions, comments, or requests?
Contact Creative Systems, Inc.

USA phone: 360-385-6212 Fax: 360-385-6213
Office hours: 7:00 am - 4:00 pm Pacific Time, Monday - Friday

Mailing address:
PO Box 1910
Port Townsend, WA 98368 USA

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