[Garry Hartshorn]

I would agree if you are going to used 3D you have to accurate to the inth degree and for that reason it is near ideal for engineering planning. Personally I start sketching by hand a basic concept then move to drawing the hull using "ProLines" which does all the basic calculations, I then export the 3D model of the hull to Rhino to make final cosmetic changes ( sheer, transom ect..anything that does not effect hydrostatics ) and proceed with drawing stations ( 5 minutes for 50 ) stations spacing is generally worked on frame spacings or a denomination of, Buttocks ( Longitudinal girders, engine bearers ect... ) Waterlines ( topside stringers ) Diagonals ( bottom stringers ) it does not allways work out but within an hour I have all the basics for the hull construction. I then usually make a 2D drawing of these elements which I export to Autocad for final touchup and presentation work for a completed lines drawing including a perspective, Autocad has by far a better 2D output than Rhino but Rhino walks all over Autocad when it comes to 3D it's great that the use compatable file formats. But all up if I have my head in gear I can do this in about 6 hours but when doing this by hand it takes me a full 2 weeks.

[Codger]

I suppose that I really ought not to be in this thread since I can't even draw a straight line with a straight-edge to help.

AMG
My point about the 6'5" engineer was not well put. I just find that when a 3d "walkthrough" can be done and there are other items in the view with which I'm familiar for scale, certain things seem to be obvious that weren't so in the drawings. 2D is great for the conceptual side.

The plasma that I'm using is a Fujitsu 4242. I have no idea what the resolution is. I'll ask the IT guy.

[Garry Hartshorn]

Regardless of drawing skills the most important thing about design is ideas and opinion and being able to put them forward.

[Garry Hartshorn]

A few years ago I was working as Captain / Engineer on a 100 ft motoryacht. The engineroom was so tight that it was nearly impossible to gain access between the engines and hull to do basic maintenance and it would have been physicaly impossible to do major work the only way that this could be done wwould have been to remove the centre engine then lift and slide the wing engine to the centre. why they went with 3 mains I have no idea as is would have been much more logical to go with the next series bigger engine to get the power and there was plenty of length and hight to accommodate this. Had a 3D model been presented to the person the yacht was built for I am sure that they would have made it so.

[rlackey]

Originally Posted by Garry Hartshorn

I then usually make a 2D drawing of these elements which I export to Autocad for final touchup and presentation work for a completed lines drawing including a perspective, Autocad has by far a better 2D output than Rhino but Rhino walks all over Autocad when it comes to 3D it's great that the use compatable file formats. But all up if I have my head in gear I can do this in about 6 hours but when doing this by hand it takes me a full 2 weeks.

Yep, I agree AutoCAD is the tool of choice for 2D. I use Rhino and AutoCAD depending on what I need to do. I can usually export just what linework I need of the 3D model to AutoCAD for a 2D drawing pretty quickly.

When I last contacted my steel supplier about laser cutting, he gave me all the specs of the file he would need, and being able to supply him with a dxf file that is basically ready for cutting can save some real money because they have to do very little manipulation of it.

Garry, you are way faster than I am! But that is down to experience I suppose. I am still learning as I go along, and I work full time running my own video and film production company, so it takes me a long time to do anything. I spent months on the hull for my current project just because I only had an hour here and there to put into it. I also started from scratch over and over a number of times, and in the end made 31 revisions to get it right.

I would like to progress now to the framing of the hull and internal structure, but I am stuck with my head in a book trying to learn and understand how to perform stress and load calculations on the hull from mast and rigging, and the keel to determine frame spacing, bulkhead placement, material thickness required and so forth. Perhaps this is more crucial in a sailing yacht where loads are perhaps quite high in certain areas than it is in a motor yacht.

Garry, how do you determine this? I'm trying to get to grips with the theory behind it but when you say you are able to get this far within an hour or so I fear I am missing something simple or overcomplicating things.

Perhaps this is a subject for a new thread, but if anyone could help I would greatly appreciate it.

Rich

[Garry Hartshorn]

Hi Rich

Yes we are getting of the original path of the thread. But as I have already doodled my ideas I am able to draw a hull in ProLines very quickly which also calculates my hydrostatics I can then refer to ABS rules or any other construction rules for the basic scantlings, plating thickness, frame spacing ect though they may change as we get further into the spiral but that is not really a big issue at this stage I also know in a steel sailing yacht that the structure around the mast will require a bulkhead of some sort to take the compression loads which I assume as the same thickness as the bottom plating and later I will look at lightening holes access holes and thining the plating. It also helps a lot to look at other similar vessels a combination of these will very quickly get you close to a suitable structure. It is pointless to calculate the stresses on a hull to the inth degree based on a rig that may need to be redesigned because of the weight of the hull is a 5% heavier than expected, you need a starting point and I find that a basic calculation and observation of similar vessels is the key. For say a 13m medium to heavy displacement ketch with a full keel I would be looking at 12mm keel plating 6mm bottom 3mm topsides frame spacing of 750mm to 800mm with 5 full bulkheads which all but the forward and aft would have major cutouts, frames and stringers would be 6mm x 50mm T section the web being 30mm ofcours this would be a lttle on the heavy side but it give you the option of sheding weight if needs be which is easier than trying to figure out how to make it stronger because you went to light. I am assuming also that this is a cruising yacht that you are designing.

I use the contour comand in Rhino for drawing sections ect... but dont forget to offset thes lines the thickness of the hull plating otherwise the boat will be a little bigger than expected and will effect the hydrostatic calculations.

Regards Garry

[rlackey]

Garry,

Thanks, I'm downloading the demo versions of Prolines and a couple of the other tools, not sure what the limitations on them are. I did my hydrostatic calculations by hand using data from the Rhino model, but I would love to run it through Prolines and see what it comes up with. Would you be willing to help if the demo version won't allow me to run the hydrostatics?

It's a 52m radius chine hull, yes it is a cruiser, but according to the calculations I came up with for the hull, it should be capable of some pretty good speed. So far I haven't found much detailed information on other vessels of a similar size to get an idea of materials. I'll keep looking though, all I'm looking for is a starting point, any rough estimates for a 52m as you gave for a typical 13m?

Where should I get a copy of ABS rules for reference?

I don't want to go off topic any more in this thread though, so can I send you a private message about this if I have more questions?

Thanks,

Rich

[archnav.de]

Today it is hard to build 3D-models from the early beginning and to keep them through the whole shipbuilding process, because of the missing interfaces between the different 3D CAD-Systems, the missing 3D-equipment models from sub suppliers(all you can get are normally 2D-dxf files) and the missing ability to handle very complex and large 3D-models in a smooth way.


But never the less before Detail Design begins the following work has to be carried out:

Ship design
Specification
Loading conditions
Intact and damage stability
Manoeuvring and Seakeeping
CFD analysis
Powering and speed
Cost estimation, budgets
Time schedule, budgets for work units
Steel scantling plan
Calculation of weights
Bill of material and schedule
Block assembly plan
Machinery layout
Piping diagrams
Current one line diagram
Equipment list
Painting plan
Outfitting plan
FE-Calculation
Noise and vibration

After delivery:

Hull Condition Monitoring
Ship Operation Monitoring

All these activities have to take the same ship and the specific conditions at the shipyard into account. These plans are often made too late, are incomplete, faulty, contradictory or too inaccurate. The reason for this is the fact, that everybody must work independently and there is no common product and production model to guarantee the transparency of the information. These partly incompatible plans finally lead to considerable disturbances and much higher costs than necessary.

The EDP development on most shipyards has gone into the following direction:

The amount of different software packages has increased
The number of data files has increased
The number of inaccurate plans has increased.




As a new starting point we are trying to build up a 3D-model store under

http://www.boatdesign.net/gallery/sh...y.php/cat/3054

As an enclosure you find a picture how to the handle the 3D-interfaces between the CAD-systems in the best way. For the Rhino people: You should work normally via Step, except for the export towards Autocad. Use here Acis 4.0. If you have the models in the three formats Parasolid (.x_t), ACIS (.sat) and STEP (.stp) available you can act with them in most CAD-Systems like native files. With .igs you get normally a lot of problems.

[Garry Hartshorn]

What a great idea, I had been drawing very crude blocks to deal with the issue of engineering equipment generally made of a selection of boxes and cylinders of the diamentions gleaned from 2D drawings that I was able to download or find in catalogs. I will be using your site in the future when I can.

Garry

[tartanski]

The 3D model database is indeed a very good idea, A few years ago I worked for a swedish company called Tribon, I was developing a database to store 10000s of parts which are required in shipbuilding.

I belive they now have more than 200,000 parts in the database.

Take a look,

www.tribon.com
The components are more suitable for large comercial shipbuilding.

[archnav.de]

tartanski


Tribon has up to now the most professional 3D model database, with an extremely amount of models. But the main parts are missing, the service is very expensive, and they have the problem to update their models. We prefer for the long run the distribution direct via sub supplier.We are starting to cooperate with MAN ( the most important engine supplier in shipbuilding). You can configured and download their models via their extranet.

Engine suppliers are the most important players in equipment design. In the end we are planning that the people will be able to download as a starting point a whole engine arrangement incl. main engine, gensets, propellers, shaft, gearbox, coupling, exhaust gas lines, silencers, filters, pumps, preheaters, steel foundation, engine room crane and so on and so on, because all these parts belong to the gensets and main engines. Just look into the project guides from the engine suppliers.


For boat design it will be great if you have some models to share. Please upload them towards to http://www.boatdesign.net/gallery/sh...y.php/cat/3054

Cheers

Bernd

[dbd]

Hallo,
I am Naval Architect with 8 years experience with different 3d software for "big shipbuilding" (Cadds5i - Trident module for hull construction, and Tribon M2 also for hull construction - only one year of experience) and also 3d sofware for Yacht designing (Rhino, Multisurf, Maxsurf). I would appreciate Your opinion about using Catia V5R16 and Unigraphics for Yacht design (Yacht design meaning not only rendering but complete structural drawings, mechanical, piping, electrical, list of materials, ...)
Thanks in advance
BRGDS

[jmr]

Hi,

I and some big shipyards in north germany are productively using Unigraphics NX for their Steel, Piping and Designworks. I can't comment on Catia, I think Tartansky is more competent on this subject. The important thing to consider is IO (export and import) and the capability to handle VERY LARGE ASSEMBLY, because shipbuilding is a very complex and big project. You can model any kind of surface with Unigraphics. In my opinion, if you already gatherd experience in any 3D software, then it will be more comfortable for you to use Unigraphics or Catia. Somebody, who only used 2D software will have problems accepting a 3D software.

Coordinating piping for example is actually building the ship digitaly. You can check clearence, collisions and you see "life" what other do. Everything is in 3D space.

Actualy you can use any 3D software, but most important for the project is to use a collaboration data format that can be used by any 3D software. The tricky part is, that you have to maintain the version of your data every day! Thats why it is better to use ONE software branch for all CAD/CAE process.


cheers,

JMR

Originally Posted by dbd

I would appreciate Your opinion about using Catia V5R16 and Unigraphics for Yacht design (Yacht design meaning not only rendering but complete structural drawings, mechanical, piping, electrical, list of materials, ...)
Thanks in advance
BRGDS

[dbd]

Hallo,
Is there Unigraphics tutorial for shipbuilding and is it possible that You send it to me (pdf)?

BGRDS
dbd

Originally Posted by jmr

Hi,

I and some big shipyards in north germany are productively using Unigraphics NX for their Steel, Piping and Designworks. I can't comment on Catia, I think Tartansky is more competent on this subject. The important thing to consider is IO (export and import) and the capability to handle VERY LARGE ASSEMBLY, because shipbuilding is a very complex and big project. You can model any kind of surface with Unigraphics. In my opinion, if you already gatherd experience in any 3D software, then it will be more comfortable for you to use Unigraphics or Catia. Somebody, who only used 2D software will have problems accepting a 3D software.

Coordinating piping for example is actually building the ship digitaly. You can check clearence, collisions and you see "life" what other do. Everything is in 3D space.

Actualy you can use any 3D software, but most important for the project is to use a collaboration data format that can be used by any 3D software. The tricky part is, that you have to maintain the version of your data every day! Thats why it is better to use ONE software branch for all CAD/CAE process.


cheers,

JMR

[tartanski]

JMR is right ,

CATIA and Unigraphics are the new breed of ship design systems, they originate from very powerful mechanical design applications, and have been developing Shipbuilding specific modules to meet the large assembly and coordination requirements of shipbuilding. Although systems like Tribon (I worked for Tribon 6 years) may have better in built in shipbuilding functionality , as it has been developed over 30 years, the new breed of systems begin to offer far greater modelling capabilities. For example, with CATIA or UG not only the steel and Systems can be designed , the complex surfaces required for yacht can be directly created and manipulated in the same system, or a customised door mechanisms can be designed, analysed and simulated all from the same GUI.

For yacht building it is very attractive to use the new breed of Systems as they will benefit from the developments funded by the larger industries using systems like CATIA , for example Aerospace and Automotive design. Shipbuilding is an industry perceived as many years behind these industries in terms of practices and design processes. With the new systems you can leverage the years of experience from these industries and implement new processes and practices.

Originally Posted by dbd

Hallo,
I am Naval Architect with 8 years experience with different 3d software for "big shipbuilding" (Cadds5i - Trident module for hull construction, and Tribon M2 also for hull construction - only one year of experience) and also 3d sofware for Yacht designing (Rhino, Multisurf, Maxsurf). I would appreciate Your opinion about using Catia V5R16 and Unigraphics for Yacht design (Yacht design meaning not only rendering but complete structural drawings, mechanical, piping, electrical, list of materials, ...)
Thanks in advance
BRGDS