-
7/27/2019 Weight Estimates of Tugs
1/3
HishamMarine engineer
Join Date: Oct 2005Rep: 28 Posts: 48
Location: Egypt
Tug Weight estimation
Could any one tell me how to estimate the light weight of a
towing and oil recovery tug(principle dimension are known)
I know a several methods based on a basis or sister ships, but I
have a shortage inavailable data so I cant use these methods
I need fast formula (not accurate but almost near)
I found this formula:
Light Weight = 0.2 (L.B.D) tons
Is this formula true?Hisham
View Public Profile
View Hisham's Gallery
Find all posts by Hisham
#2
04-25-2006, 12:00 AM
ehardimanSenior Member
Join Date: Aug 2004Rep: 1915 Posts: 1,821
Location: Port Orchard, Washington, USA
If in meters, more like 0.5*L*B*T = tonnes Where L = LWL, B=max
beam waterline, and T
= midships keel draft.
How you measure D (depth of hold) or T (draft) is the key for
these "rule of thumb"
"calculations".
jehardiman
View Public Profile
View jehardiman's Gallery
Find all posts by jehardiman
#3
04-25-2006, 07:03 AM
HishamMarine engineer
Join Date: Oct 2005Rep: 28 Posts: 48
Location: Egypt
Your formula can be used to determine weight of an existing tug
(has a known draft)
This equation based on Cb and Cp that they vary from (4.5 5.5)
for tugs
http://www.boatdesign.net/forums/profile/hisham.htmlhttp://www.boatdesign.net/forums/profile/hisham.htmlhttp://www.boatdesign.net/forums/profile/hisham.htmlhttp://www.boatdesign.net/forums/profile/hisham.htmlhttp://www.boatdesign.net/gallery/showgallery.php/cat/500/ppuser/11233http://www.boatdesign.net/forums/search.php?do=finduser&u=11233http://www.boatdesign.net/forums/boat-design/tug-weight-estimation-11424.html#post85240http://www.boatdesign.net/forums/boat-design/tug-weight-estimation-11424.html#post85240http://www.boatdesign.net/forums/profile/jehardiman.htmlhttp://www.boatdesign.net/forums/profile/jehardiman.htmlhttp://www.boatdesign.net/forums/profile/jehardiman.htmlhttp://www.boatdesign.net/forums/profile/jehardiman.htmlhttp://www.boatdesign.net/gallery/showgallery.php/cat/500/ppuser/4901http://www.boatdesign.net/gallery/showgallery.php/cat/500/ppuser/4901http://www.boatdesign.net/forums/search.php?do=finduser&u=4901http://www.boatdesign.net/forums/search.php?do=finduser&u=4901http://www.boatdesign.net/forums/boat-design/tug-weight-estimation-11424.html#post85274http://www.boatdesign.net/forums/boat-design/tug-weight-estimation-11424.html#post85274http://www.boatdesign.net/forums/profile/hisham.htmlhttp://www.boatdesign.net/forums/profile/hisham.htmlhttp://www.boatdesign.net/forums/newreply.php?do=newreply&p=85240http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85221http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85240http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85221http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85240http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85221http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85240http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85221http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85240http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85221http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85240http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85221http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85240http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85221http://www.boatdesign.net/forums/profile/hisham.htmlhttp://www.boatdesign.net/forums/boat-design/tug-weight-estimation-11424.html#post85274http://www.boatdesign.net/forums/search.php?do=finduser&u=4901http://www.boatdesign.net/gallery/showgallery.php/cat/500/ppuser/4901http://www.boatdesign.net/forums/profile/jehardiman.htmlhttp://www.boatdesign.net/forums/profile/jehardiman.htmlhttp://www.boatdesign.net/forums/boat-design/tug-weight-estimation-11424.html#post85240http://www.boatdesign.net/forums/search.php?do=finduser&u=11233http://www.boatdesign.net/gallery/showgallery.php/cat/500/ppuser/11233http://www.boatdesign.net/forums/profile/hisham.htmlhttp://www.boatdesign.net/forums/profile/hisham.html
-
7/27/2019 Weight Estimates of Tugs
2/3
What I need is to estimate the light weight in first design
stage, then I can make a
prediction of draft on witch the coming steps of design will
depend on
Hisham
View Public Profile
View Hisham's Gallery
Find all posts by Hisham
#4
04-26-2006, 11:56 AM
ehardimanSenior Member
Join Date: Aug 2004Rep: 1915 Posts: 1,821Location: Port Orchard,
Washington, USA
You have it backwards, in the classic design spirial...
1) select L, B, and T first from shape/tonnage laws/mission
considerations
2) draw the lines and curves of form3) do the structural
weight/strength4) add the propulsion, outfit, and stores/cargo
5) check against the L, B, and T, and around the design spirial
again.
If what you want is a quick and dirty structural weight then
here is a way to get close.
shell weight = surface area of the hull * plating weightdeck
weight = surface area of the decks * plating weightplating weight =
shell weight +deck weight
structure weight = 50-70% of plating weight
light ship weight = plating weight + structure weight+ machinery
weight + 7% of the totalother weights for paint and
welds/fastenings.
jehardiman
View Public Profile
View jehardiman's Gallery
Find all posts by jehardiman
#5
04-27-2006, 10:06 AM
GuillermoIngeniero Naval
Join Date: Mar 2005Rep: 2131 Posts: 3,592Location: Pontevedra,
Spain
According to my notes on tugs, a first approach to displacement
in light ship condition(WR), when in the first stages of design,
is:0.24*L*B*D < WR < 0.29*L*B*D (Metric units) (L =Lpp)
For ice-going heavy reinforced tugs, superior limit may go up to
0.34*L*B*H
__________________Guillermo Gefaell
http://www.boatdesign.net/forums/profile/hisham.htmlhttp://www.boatdesign.net/forums/profile/hisham.htmlhttp://www.boatdesign.net/gallery/showgallery.php/cat/500/ppuser/11233http://www.boatdesign.net/forums/search.php?do=finduser&u=11233http://www.boatdesign.net/forums/boat-design/tug-weight-estimation-11424.html#post85471http://www.boatdesign.net/forums/boat-design/tug-weight-estimation-11424.html#post85471http://www.boatdesign.net/forums/profile/jehardiman.htmlhttp://www.boatdesign.net/forums/profile/jehardiman.htmlhttp://www.boatdesign.net/forums/profile/jehardiman.htmlhttp://www.boatdesign.net/forums/profile/jehardiman.htmlhttp://www.boatdesign.net/gallery/showgallery.php/cat/500/ppuser/4901http://www.boatdesign.net/gallery/showgallery.php/cat/500/ppuser/4901http://www.boatdesign.net/forums/search.php?do=finduser&u=4901http://www.boatdesign.net/forums/search.php?do=finduser&u=4901http://www.boatdesign.net/forums/boat-design/tug-weight-estimation-11424.html#post85643http://www.boatdesign.net/forums/boat-design/tug-weight-estimation-11424.html#post85643http://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/newreply.php?do=newreply&p=85471http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85274http://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/newreply.php?do=newreply&p=85471http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85274http://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/newreply.php?do=newreply&p=85471http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85274http://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/newreply.php?do=newreply&p=85471http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85274http://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/newreply.php?do=newreply&p=85471http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85274http://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/newreply.php?do=newreply&p=85471http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85274http://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/newreply.php?do=newreply&p=85471http://www.boatdesign.net/forums/newreply.php?do=newreply&p=85274http://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/boat-design/tug-weight-estimation-11424.html#post85643http://www.boatdesign.net/forums/search.php?do=finduser&u=4901http://www.boatdesign.net/gallery/showgallery.php/cat/500/ppuser/4901http://www.boatdesign.net/forums/profile/jehardiman.htmlhttp://www.boatdesign.net/forums/profile/jehardiman.htmlhttp://www.boatdesign.net/forums/boat-design/tug-weight-estimation-11424.html#post85471http://www.boatdesign.net/forums/search.php?do=finduser&u=11233http://www.boatdesign.net/gallery/showgallery.php/cat/500/ppuser/11233http://www.boatdesign.net/forums/profile/hisham.html
-
7/27/2019 Weight Estimates of Tugs
3/3
Gestenaval S.L., Naval Architecture & Marine EngineeringMoon
Yacht Design
Guillermo
View Public Profile
View Guillermo's Website
View Guillermo's Gallery
Find all posts by Guillermo
#6
04-27-2006, 10:25 AM
GuillermoIngeniero Naval
Join Date: Mar 2005Rep: 2131 Posts: 3,592Location: Pontevedra,
Spain
A second way of estimating WR, is:
WR = k1*L*B*D + k2*PB (being PB the propulsive power in kW)
k1 varies between 0.18 and 0.26
k2 varies between 0.08 and 0.1__________________Guillermo
Gefaell
Gestenaval S.L., Naval Architecture & Marine Engineering
http://www.gestenaval.com/http://www.gestenaval.com/http://www.moonyachtdesign.com/http://www.moonyachtdesign.com/http://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.gestenaval.com/http://www.gestenaval.com/http://www.boatdesign.net/gallery/showgallery.php/cat/500/ppuser/8178http://www.boatdesign.net/gallery/showgallery.php/cat/500/ppuser/8178http://www.boatdesign.net/forums/search.php?do=finduser&u=8178http://www.boatdesign.net/forums/boat-design/tug-weight-estimation-11424.html#post85645http://www.boatdesign.net/forums/boat-design/tug-weight-estimation-11424.html#post85645http://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.gestenaval.com/http://www.gestenaval.com/http://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/newreply.php?do=newreply&p=85643http://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/newreply.php?do=newreply&p=85643http://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/newreply.php?do=newreply&p=85643http://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/newreply.php?do=newreply&p=85643http://www.gestenaval.com/http://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.boatdesign.net/forums/boat-design/tug-weight-estimation-11424.html#post85645http://www.boatdesign.net/forums/search.php?do=finduser&u=8178http://www.boatdesign.net/gallery/showgallery.php/cat/500/ppuser/8178http://www.gestenaval.com/http://www.boatdesign.net/forums/profile/guillermo.htmlhttp://www.moonyachtdesign.com/http://www.gestenaval.com/
