Good morning to all modelers.
Before including in the list of the first message, the data from the models of Ronald, Scratchbuilder and others (who kindly gave me permission to do so) I would like to analyze the first results.
Anyone who has done statistics (at least one exam) knows very well that these data are too few for a serious scientific analysis, but we do it for pleasure.
It is useless to repeat what I have already written.
Actually no, maybe it's not useless but I don't want to rewrite the same things with the risk of boring people and making this message too heavy.
Therefore anyone who wants can read message no. 11 of this topic.
Furthermore:
Italcantieri engineers certainly won't come to visit us to get information on how to build the propellers and how to size them.
But a beginner (who doesn't have a kit or a reference model) who doesn't know which propeller to put in and who is making a model the same or similar to yours, could have good information.
This is the meaning and possible practical usefulness of the document.
Oh by the way! Because of this research, I'm looking at RC scale model kits, I was surprised, the costs are really high.
The problem for the modeller, without a kit and without a reference project, who wants to build a model from scratch or restore one without a propeller or make RC a static model, is that the information on the propellers is a bit scattered.
Now this information is found in three different topics ("Proportions between ship size and propeller diameter " - "manufacturers and sellers of nautical propellers for rc model building " and - "Do we want to talk about propellers?") but I hope the search with the word PROPELLER produces its results.
But now we come to the data collected so far.
So far, the section with the most data is the one relating to tugboats and work boats.
It's normal for this to be the case, in fact I've noticed that among RC modelers it's the most popular category (I really like it too).
I didn't think the range was so limited (shots not scattered, excellent), yet even in this section there are many variables and at least two subsections should be created between the tugs:the port ones (stockier) and the oceanic ones (slender).
We are between 1:16.5 and 1:22.
From the port to the ocean.
The modeler who wants to delve deeper, after reading this ratio, can have a general idea, but then can go and see ColinH's, or Wolle's, etc. model in detail. etc., and discover more details (by analyzing those variables in concrete terms).
Even including fishing, rescue, fire, police and pleasure vessels the range is still very narrow with more central data. 1:19 to 1:26.
From 1:16.5 to 1:26.
By reading the information carefully, anyone with a little attention already understands that even in the modeling field, a tug or a fishing boat has a relatively low ratio.
The tugboat with a nice diameter available, short wheelbase is like a car that climbs uphill. Capable of notable efforts (as ColinH testified with his amazing anecdote) but incapable of useless high speeds.
Modern warships are different.
The ratio rises and reaches (for now) a range between 1:30 and 1:34, but I am convinced that it could rise much further. We'll see with the next data.
I remember that there could be a lot of difference between real ships and models in this length/propeller ratio and this will be interesting to verify.
I'm very curious about battleships from the Second World War; I would be very curious to compare the data of the real ones collected so far with scale models.
However, it is very difficult to find RC sailing scale battleships.
Yet I remember seeing them in this forum too.
Some fields are still empty or too sparse.
Proportions between ship size and propeller diameter
Good morning to all modelers.
Before including in the list of the first message, the data from the models of Ronald, Scratchbuilder and others (who kindly gave me permission to do so) I would like to analyze the first results.
Anyone who has done statistics (at least one exam) knows very well that these data are too few for a serious scientific analysis, but we do it for pleasure.
It is useless to repeat what I have already written.
Actually no, maybe it's not useless but I don't want to rewrite the same things with the risk of boring people and making this message too heavy.
Therefore anyone who wants can read message no. 11 of this topic.
Furthermore:
Italcantieri engineers certainly won't come to visit us to get information on how to build the propellers and how to size them.
But a beginner (who doesn't have a kit or a reference model) who doesn't know which propeller to put in and who is making a model the same or similar to yours, could have good information.
This is the meaning and possible practical usefulness of the document.
Oh by the way! Because of this research, I'm looking at RC scale model kits, I was surprised, the costs are really high.
The problem for the modeller, without a kit and without a reference project, who wants to build a model from scratch or restore one without a propeller or make RC a static model, is that the information on the propellers is a bit scattered.
Now this information is found in three different topics ("Proportions between ship size and propeller diameter " - "manufacturers and sellers of nautical propellers for rc model building " and - "Do we want to talk about propellers?") but I hope the search with the word PROPELLER produces its results.
But now we come to the data collected so far.
So far, the section with the most data is the one relating to tugboats and work boats.
It's normal for this to be the case, in fact I've noticed that among RC modelers it's the most popular category (I really like it too).
I didn't think the range was so limited (shots not scattered, excellent), yet even in this section there are many variables and at least two subsections should be created between the tugs:the port ones (stockier) and the oceanic ones (slender).
We are between 1:16.5 and 1:22.
From the port to the ocean.
The modeler who wants to delve deeper, after reading this ratio, can have a general idea, but then can go and see ColinH's, or Wolle's, etc. model in detail. etc., and discover more details (by analyzing those variables in concrete terms).
Even including fishing, rescue, fire, police and pleasure vessels the range is still very narrow with more central data. 1:19 to 1:26.
From 1:16.5 to 1:26.
By reading the information carefully, anyone with a little attention already understands that even in the modeling field, a tug or a fishing boat has a relatively low ratio.
The tugboat with a nice diameter available, short wheelbase is like a car that climbs uphill. Capable of notable efforts (as ColinH testified with his amazing anecdote) but incapable of useless high speeds.
Modern warships are different.
The ratio rises and reaches (for now) a range between 1:30 and 1:34, but I am convinced that it could rise much further. We'll see with the next data.
I remember that there could be a lot of difference between real ships and models in this length/propeller ratio and this will be interesting to verify.
I'm very curious about battleships from the Second World War; I would be very curious to compare the data of the real ones collected so far with scale models.
However, it is very difficult to find RC sailing scale battleships.
Yet I remember seeing them in this forum too.
Jumpugly - I wasn't reading it properly! For some reason I was thinking of the length in millimetres. What makes it particularly bad is that I was a designer in the building industry for over 40 years and worked in metric for many of them! Mainly millimetres and metres though and rarely use centimetres for anything. In my defence I posted after travelling and blame it on brain fog!
Chris
Proportions between ship size and propeller diameter
Jumpugly - I wasn't reading it properly! For some reason I was thinking of the length in millimetres. What makes it particularly bad is that I was a designer in the building industry for over 40 years and worked in metric for many of them! Mainly millimetres and metres though and rarely use centimetres for anything. In my defence I posted after travelling and blame it on brain fog!
Hi,
"played around with the scale calculator".
Did the same with Titanic's props Jump.
7.2m comes out at 0.19459m or 19.46cm (7.66") as you predicted.👍
BTW; did you know that her centre prop was smaller? 5.2m.
😎
Proportions between ship size and propeller diameter
Hi,
"played around with the scale calculator".
Did the same with Titanic's props Jump.
7.2m comes out at 0.19459m or 19.46cm (7.66") as you predicted.👍
BTW; did you know that her centre prop was smaller? 5.2m.
😎
Young at heart 😉 Slightly older in other places.😊 Cheers Doug
Doug: I just grabbed Alessandro's scale notes in the original post and played around with the scale calculator. I am sorry for all the confusion. However, I did enjoy myself!
😂🤣😂
Titanic "Real Length" below converted to 1:37th scale.
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Proportions between ship size and propeller diameter
Doug: I just grabbed Alessandro's scale notes in the original post and played around with the scale calculator. I am sorry for all the confusion. However, I did enjoy myself!
😂🤣😂
Titanic "Real Length" below converted to 1:37th scale.
Proportions between ship size and propeller diameter
There have been books published by navel architects on the subject of propellers primarily for the cruiser and off shore sailor.
AustinG🤔
AustinG
Hi Chris,
I can't fault Jumpugly's calculations.
What I wonder though is why he chose those peculiar scales!
Which result in gigantic models which no one can or will ever build.
(James Cameron and Fox studios excluded!)
Cheers, Doug😎
Proportions between ship size and propeller diameter
Hi Chris,
I can't fault Jumpugly's calculations.
What I wonder though is why he chose those peculiar scales!
Which result in gigantic models which no one can or will ever build.
(James Cameron and Fox studios excluded!)
Cheers, Doug😎
Young at heart 😉 Slightly older in other places.😊 Cheers Doug
Hi Doug, buonasera a te, everything you write is accurate.
I can sign it now.
Among the many things you said, perhaps the most important is that there are many variations.
But I stated this from the beginning.
Mine was a question, in fact I wrote:
"Is it possible to find a very generic rule for sizing the propeller of a model based on the type of ship?"
The analysis must be done for each individual category and I think I will further branch the typologies.
It is clear that a small harbor tug cannot be compared to the Yamato.
Let's see if a sort of relationship emerges in the guise of homogeneous types of boats (size, purpose and era).
We'll see if anything comes out later. If nothing comes out, no one got hurt. But I don't feel like answering no right away. A priori.
I agree with you on the inclusion (to have a more complete and truthful analysis) of many more parameters and not just the length of the vessel, weight and diameter (I assure you that in addition to those you mentioned I can think of many more).
I simplified it because it is already difficult to find this data around or among modellers, if I start asking for the length on the waterline in addition to other parameters (which, moreover, many do not know) no one would answer me and I would not have any data.
At the end of the game, I will give you an interpretative report of the data collected and, if no relationship emerges even in broad terms, I will be the first to admit it without problems.
P.S. When I write it's because I can't work on my ship models.
However, the use of time is subjective, if it were considered important only to build, this forum would not exist.
And then remember that you are Fleet Admiral, so you will have written something in these years in addition to building magnificent and stupendous naval models.
Proportions between ship size and propeller diameter
Hi Doug, buonasera a te, everything you write is accurate.
I can sign it now.
Among the many things you said, perhaps the most important is that there are many variations.
But I stated this from the beginning.
Mine was a question, in fact I wrote:
"Is it possible to find a very generic rule for sizing the propeller of a model based on the type of ship?"
The analysis must be done for each individual category and I think I will further branch the typologies.
It is clear that a small harbor tug cannot be compared to the Yamato.
Let's see if a sort of relationship emerges in the guise of homogeneous types of boats (size, purpose and era).
We'll see if anything comes out later. If nothing comes out, no one got hurt. But I don't feel like answering no right away. A priori.
I agree with you on the inclusion (to have a more complete and truthful analysis) of many more parameters and not just the length of the vessel, weight and diameter (I assure you that in addition to those you mentioned I can think of many more).
I simplified it because it is already difficult to find this data around or among modellers, if I start asking for the length on the waterline in addition to other parameters (which, moreover, many do not know) no one would answer me and I would not have any data.
At the end of the game, I will give you an interpretative report of the data collected and, if no relationship emerges even in broad terms, I will be the first to admit it without problems.
P.S. When I write it's because I can't work on my ship models.
However, the use of time is subjective, if it were considered important only to build, this forum would not exist.
And then remember that you are Fleet Admiral, so you will have written something in these years in addition to building magnificent and stupendous naval models.
Bona sera Alessandro,
I fear that you are 'on a hunt for an aggravated aquatic fowl' here🤔
I don't believe that that there CAN be a simple relationship between vessel length and propeller size. Too many other important factors are being ignored.
Of course you can accumulate much data from many modellers and attempt to find a relationship that fits the proportions theory. I'm reminded of two wise sayings about statistics-
There are lies, damn lies ... and statistics, or
Never trust statistics that you haven't falsified yourself.
First off: I believe that your correspondents on this matter are reporting the LoA (overall length) of their models. When what actually counts is the LWL (waterline length). Check out our old friend Mr William Froude in this respect.
Other factors not accounted for-
WL Length to beam ratio.
I think it is fairly well known that a long thin ship will travel faster, for the same given power input power, as a short fat vessel. (Mr Froude again!) No surprise that destroyers generally have an LtoB ratio of around 10+, whereas tugs are probably around 3:1 or less.
Hull form.
Displacement or planing?
Fast interceptor / racer or commercial vessel; workboat, freighter (bulk carrier vs container), cruise ship ...
Type of prop-
Designed for speed or thrust and economy? Pitch? Purpose of the vessel?
Just my thunks for mainly scale models.
Obviously the out and out racers (which I am NOT) have their own 'rules of thumb'.
Good luck with your endeavour Alessandro, but I think it is probably a futile exercise and the time could be better spent working on your wonderful models.
Ciao, Doug😎
Proportions between ship size and propeller diameter
Bona sera Alessandro,
I fear that you are 'on a hunt for an aggravated aquatic fowl' here🤔
I don't believe that that there CAN be a simple relationship between vessel length and propeller size. Too many other important factors are being ignored.
Of course you can accumulate much data from many modellers and attempt to find a relationship that fits the proportions theory. I'm reminded of two wise sayings about statistics-
There are lies, damn lies ... and statistics, or
Never trust statistics that you haven't falsified yourself.
First off: I believe that your correspondents on this matter are reporting the LoA (overall length) of their models. When what actually counts is the LWL (waterline length). Check out our old friend Mr William Froude in this respect.
Other factors not accounted for-
WL Length to beam ratio.
I think it is fairly well known that a long thin ship will travel faster, for the same given power input power, as a short fat vessel. (Mr Froude again!) No surprise that destroyers generally have an LtoB ratio of around 10+, whereas tugs are probably around 3:1 or less.
Hull form.
Displacement or planing?
Fast interceptor / racer or commercial vessel; workboat, freighter (bulk carrier vs container), cruise ship ...
Type of prop-
Designed for speed or thrust and economy? Pitch? Purpose of the vessel?
Just my thunks for mainly scale models.
Obviously the out and out racers (which I am NOT) have their own 'rules of thumb'.
Good luck with your endeavour Alessandro, but I think it is probably a futile exercise and the time could be better spent working on your wonderful models.
Ciao, Doug😎
Young at heart 😉 Slightly older in other places.😊 Cheers Doug
Hi Chris: It is deceptive for sure. When you consider the Vriginio Fasan at 482.3cm long at 1:30th scale you are getting a model that is 189 3/4 inches long or 11' and 1/2 feet long with a 16cm prop which equals 6 1/2 inches.
The Titanic at 1:37th scale is 286 inches long (almost 24 feet) with a group of 7.5 inch props.
I was just converting the real ship and prop lengths to the scale that Alessandro listed for each boat, which was in fact not exactly what he was looking for. I use the scale converter to size out various subassemblies on my kits (both boats and planes) that may not seem correct to me. The converter I use online is a huge help for proper airplane propeller dimensions when what a manufacturer may supply is miles off base. The same applies to ships figures etc.
I admit that I am a bit scale obsessed, as I usually get subassemblies 3D printed to the exact proportions I will need if the ones that may come with the kit are obviously wrong. 😊
Proportions between ship size and propeller diameter
Hi Chris: It is deceptive for sure. When you consider the Vriginio Fasan at 482.3cm long at 1:30th scale you are getting a model that is 189 3/4 inches long or 11' and 1/2 feet long with a 16cm prop which equals 6 1/2 inches.
The Titanic at 1:37th scale is 286 inches long (almost 24 feet) with a group of 7.5 inch props.
I was just converting the real ship and prop lengths to the scale that Alessandro listed for each boat, which was in fact not exactly what he was looking for. I use the scale converter to size out various subassemblies on my kits (both boats and planes) that may not seem correct to me. The converter I use online is a huge help for proper airplane propeller dimensions when what a manufacturer may supply is miles off base. The same applies to ships figures etc.
I admit that I am a bit scale obsessed, as I usually get subassemblies 3D printed to the exact proportions I will need if the ones that may come with the kit are obviously wrong. 😊
I'm gathering information.
In order for the first message to be of some use and consultable by anyone who asks the question (what diameter should I choose for my ship if I don't have a project or a reference kit?) I should include at least six models for each type.
Have patience and trust, ahahahahahah.
Proportions between ship size and propeller diameter
I'm gathering information.
In order for the first message to be of some use and consultable by anyone who asks the question (what diameter should I choose for my ship if I don't have a project or a reference kit?) I should include at least six models for each type.
Have patience and trust, ahahahahahah.
I'm with you Jumpugly👍
Ran across that converter a year or so ago. Bookmarked since.
Most useful for calculating a practical scale for models of large ships, carriers etc.
As well as bits n pieces carried on board, and props as you say.
Always provided that you can 'get your eyeballs' on the data of the original!
Cheers, Doug😎
Proportions between ship size and propeller diameter
I'm with you Jumpugly👍
Ran across that converter a year or so ago. Bookmarked since.
Most useful for calculating a practical scale for models of large ships, carriers etc.
As well as bits n pieces carried on board, and props as you say.
Always provided that you can 'get your eyeballs' on the data of the original!
Cheers, Doug😎
Young at heart 😉 Slightly older in other places.😊 Cheers Doug
Alessandro:
Note: These are only scale conversions from the full size measurements you posted and not a "rule" for proportional sizing of propellers for r/c applications. 😉
Virginio Fasan 1:30 scale length 482.3cm, prop size 16cm
Roma 1:52 scale length 462.89cm, prop size 8.6cm
Bismark 1:53 scale length 473.6cm, prop size 8.9cm
Titanic 1:37 scale length 727cm, prop size 19.4cm
QE-2. 1:43 scale length 683.7 cm, prop size 15.5cm
Proportions between ship size and propeller diameter
Alessandro:
Note: These are only scale conversions from the full size measurements you posted and not a "rule" for proportional sizing of propellers for r/c applications. 😉
Alessandro! May not be a rule per se, but I always put the numbers through my favorite scale converter...for example: the "Caio Duilio" propeller would 15cm in 1:32 scale with a ship length of 477.8125cm. But, here it is. I can't live without it! 😉
https://www.ginifab.com/feeds/cm_to_inch/scale_converter.html
Proportions between ship size and propeller diameter
Alessandro! May not be a rule per se, but I always put the numbers through my favorite scale converter...for example: the "Caio Duilio" propeller would 15cm in 1:32 scale with a ship length of 477.8125cm. But, here it is. I can't live without it! 😉
Is it possible to find a very generic rule for sizing the propeller of a model based on the type of ship?
I will re-edit this message whenever there is information to add
There is no doubt that the vast majority of RC naval modelers use the propeller that is supplied in the kit or indicated in the project.
However, it is possible that someone will have to choose it themselves.
As already mentioned, few are looking for the most efficient or most suitable propeller.
I believe that those most interested in the very precise choice, or rather forced by necessity, are the model makers who build fast hulls.
I would like to collect statistics on the models already created.
The first to give us a general indication is Boatshed, according to him:
for a model approximately 45 to 53 cm long, a propeller of 25 mm and above is fine.
for a model approximately 107 cm long, a propeller of 40 mm and above is fine.
Boatshed makes no reference to the weight of the vessel.
It's an excellent start and it's a very valuable indication because it's concrete and pragmatic
For the latest RC naval model in 1/60 scale, 94.5 cm long (excluding the bowsprit) and weighing approximately 5 kg, I used a 40 mm diameter three-bladed plastic propeller.
For the diameter I respected the scale of the time even if the shape was different.
The choice of material and number of blades was dictated only by the fact that it was a very common and cheap propeller.
I am satisfied with the performance and I consciously oversized the choice of engine power.
As regards the number of blades, I believe that the choice is mostly random but it ranges from two to three blades for fast motorboats and from 3 to 4 blades for all the others.
The ratio varies greatly depending on the type of vessel.
__________
TUGS AND WORK BOATS
1 Progress J-502 by Ronald.
Length 38.1 cm, (weight 0.635 kg) a two-bladed nylon propeller with a diameter of 25 mm.
Drive type: ?
Propeller diameter/boat length ratio = 1:15.
2. Miss Katherine tugboat by Ronald.
Length 58.42 cm, (weight 1.54 kg) a three-bladed brass propeller with a diameter of 40 mm.
Drive type: ?
Propeller diameter/boat length ratio = 1:15.
3. Westeriffe by ColinH.
Length 99 cm, (weight 10 kg) a single three-bladed propeller with a diameter of 60 mm.
Gear drive.
Propeller diameter / boat length ratio = 1 : 16.5
4. Ville Class Tugboat by Ronald.
Length 76.2 cm, (weight 3.5 kg) a four-bladed brass propeller with a diameter of 45 mm.
Drive type: ?
Propeller diameter/boat length ratio = 1:17.
5. Zwarte Zee by Wolle.
Length 88.9 cm, (weight 4 kg) a single four-bladed brass propeller with a diameter of 50 mm.
Direct drive.
Propeller diameter/boat length ratio = 1 : 18
(The propeller originally supplied was a three-bladed plastic one)
6. Danny Boy by GaryLC
Length 109.22 cm, (weight ? kg) a five-bladed propeller with a diameter of 60 mm.
Drive type: direct.
true steam propulsion
Propeller diameter/boat length ratio = 1 : 18.
7. Lady Marian of GaryLC
Length 106.68 cm, (weight ? kg) a four-bladed propeller with a diameter of 55 mm.
Drive type: geared.
true steam propulsion
Propeller diameter/boat length ratio = 1 : 19.
8. Oceanic by Wolle.
Length 105 cm, (weight approximately 5 kg), two four-bladed brass propellers, with a diameter of 48 mm.
Ratio between length and diameter = 1 : 22.
9. Rau IX of Wolle.
Length 104 cm, (weight 5 kg), four-bladed plastic propeller, with a diameter of 50 mm.
Drive type: direct.
Ratio between length and diameter = 1 : 21.
FISHING BOATS
1. Highlander Clyde Puffer by GaryLC
Length 86.36 cm, (weight 8 kg) a single four-bladed propeller with a diameter of 55 mm.
Drive type: chain.
Real steam engine.
Propeller diameter/boat length ratio = 1:16
2. Krabbenkutter Tön 12 by Wolle.
Length 50 cm, (weight 2 kg), a three-bladed plastic propeller, with a diameter of 26 mm.
Drive Type: direct.
Ratio between length and diameter = 1 : 19.
PWB and boats of similar features even if with different destination.
1. U.S. Coast Guard PCB, patrol waterways boat Sprinkles by CommodoreH
Length 81.28 cm, (weight kg) two three-bladed propellers with a diameter of 45 mm.
Drive type: geared.
Propeller diameter/boat length ratio = 1 : 18.
2. Sylvie (ex Lotse) by Mike Stoney
Length 53.34 cm, (weight 1 kg) a two-bladed propeller with a diameter of 30 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1 : 18.
RESCUE OR FIRE-FIGHTING BOATS
1. (Fire Boat) Mk2 firefloat 93 by ColinH
Length 86 cm, (weight unknown) a single three-bladed propeller with a diameter of 45 mm.
Drive type: direct.
Propeller diameter / boat length ratio = 1 : 19
2. (Fire Boat) 34" Aerokits Crash Tender by Steven (Fireboat)
Length 86.36 cm, (unknown weight) a single two-bladed propeller with a diameter of 40 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1 : 22
POLICE BOAT
1. Flaxbybuck Sea Queen Police Boat PL502
Length 88.9 cm, (weight ? kg) a two-bladed propeller with a diameter of 45 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1 : 20
LIFE BOAT
1. City of Sheffield by Rogal118
Length 111,76 cm, (weight ? kg) a Two four-bladed propellers with a diameter of 45 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1 : 25
PLEASURE CABIN MOTORBOATS
1. Fairey Huntsman by ColinH
Length 83.82 cm, (weight unknown) a single two-bladed propeller with a diameter of 35 mm.
Drive type: geared.
Propeller diameter/boat length ratio = 1 : 24.
2. Sea scout by ColinH
Length 60.96 cm, (weight unknown) a single two-bladed propeller with a diameter of 30 mm.
Drive type: belt.
Propeller diameter/boat length ratio = 1 : 20.
3. MV Caroline by ColinH
Length 142.24 cm, (weight 13 kg) a single four-bladed propeller with a diameter of 75 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1 : 19.
4. Felix from Flaxbybuck
Length 63.5 cm, (weight ? kg) a two-bladed propeller with a diameter of 30 mm.
Drive type: direct
Propeller diameter/boat length ratio = 1 : 21
5. Sea Queen by Flaxbybuck
Length 116.84 cm, (weight ? kg) a two-bladed propeller with a diameter of 45 mm.
Drive type: direct
Propeller diameter/boat length ratio = 1:26
6. Midwest Cranberry Isle by Ronald.
Length 76.2 cm, (weight 2.7 kg) a three-bladed nylon propeller with a diameter of 42 mm.
Drive type: ?
Propeller diameter/boat length ratio = 1 : 18.
7. Saint Pierre Dory by Ronald.
Length 63.5 cm, (weight 1.63 kg) a two-bladed nylon propeller with a diameter of 28 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1:23.
FAST MOTORBOATS (SLIM SHAPE LIKE THE TYPHOON)
1. Typhoon by River Rat.
Length 101.6 cm, (weight ? kg) a three-bladed propeller with a diameter of 35 mm (or 37 mm).
Drive type: direct.
Propeller diameter/boat length ratio = 1 : 29 (or 1:27).
2. 1930 Chris craft runabout (Driftwood) by River Rat
Length 91.44 cm, (weight ? kg) a three-bladed propeller with a diameter of 35 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1:26.
FERRY
1. Caltex Lumba Lumba di Jumpugly.
Lunghezza 100,33 cm (lungo fuori tutto), (peso 3 – 3,5 kg), una sola elica in Nylon del diametro di 30 mm.
Rapporto diametro elica/lunghezza barca = 1 : 33
OIL TANKERS
1. Deutschland Esso oil tanker by JockScott.
Length 174 cm, (estimated weight 32 kg) a single four-bladed propeller with a diameter of 50 mm.
Propeller diameter/boat length ratio = 1:35
CARGO SHIPS
MODERN WARSHIPS
1. Asheville class gunboat DEFIANCE by CommodoreH
Length 152.4 cm, (weight unknown) double helix with a diameter of 45 mm.
Drive type: belt.
Propeller diameter/boat length ratio = 1:34
2. Italian missile launcher "Caio Duilio"
True ship length 152.9 meters, two propellers, true propeller diameter 4.8 meters.
Propeller diameter / boat length ratio = 1:32
3. Italian frigate "Virginio Fasan"
True ship length 144.7 meters, two propellers, true propeller diameter 4.8 meters.
Propeller diameter / boat length ratio = 1:30
4. USS Arleigh Burke (DDG 51)
Length 153.9 metres, two five-bladed propellers with variable pitch and a diameter of 5.18 metres.
Real ship, not a model.
Propeller diameter/boat length ratio = 1:30.
SECOND WORLD WAR WARSHIPS
(The number of propellers must always be taken into consideration)
BATTLESHIP
1. Italian battleship Roma
Effective length of the vessel 240.7 meters, four propellers, true diameter of two propellers 4.5 meters in diameter and two propellers 4.6 meters.
Propeller diameter/boat length ratio = 1:52
2. German battleship Bismark.
True ship length 251 meters, three propellers, true propeller diameter 4.7 meters.
Propeller diameter / boat length ratio = 1:53
TOWN-CLASS LIGHT CRUISER
1. HMS Belfast C35 Graupner by Scratchbuilder.
Length 124.46 cm, (weight ? kg) four 3-bladed propellers with a diameter of 25 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1:50.
DESTROYERS
1. USS Fletcher of Toradog.
Length 238.76 cm, (weight 30 kg) two three-bladed propellers with a diameter of 75 mm.
Transmission: Direct.
Propeller diameter/boat length ratio = 1:32.
M.A.S. MOTOSCAFI ARMATI SILURANTI (MOTOR TORPEDO BOATS)
1. Schnellboat by Scratchbuilder.
Length 99.06 cm, (weight ? kg) two three-bladed propellers with a diameter of 30 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1:33.
2. Vosper MBT by Ronald.
Length 63.5 cm, (weight 1.45 kg) a three-bladed nylon propeller with a diameter of 25 mm.
Drive type: ?.
Propeller diameter/boat length ratio = 1:25.
3. MAS 562 (Motoscafo Armato Silurante) by Roy (CB90).
Length 75 cm, (weight) two three-bladed plastic propellers with a diameter of 35 mm.
Driving type: direct.
Propeller diameter/boat length ratio = 1 : 21.
FLOWER-CLASS CORVETTE
1. HMS Buttercup K193 by Scratchbuilder.
Length 86.36 cm, (weight kg) a three-bladed propeller with a diameter of 40 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1 : 22
TRANSATLANTICS
1. RMS Titanic
True ship length 269 meters, three propellers, true propeller diameter 7.2 meters.
Propeller diameter / boat length ratio = 1:37
2. RMS Titanic by another model maker not from this forum.
Length 72 cm, (approximate weight 3.5 kg) three propellers with a diameter of 20 mm.
Drive type: gear.
Propeller diameter/boat length ratio = 1:36.
2. Queen Elizabeth 2
True ship length 294 meters, two propellers, true propeller diameter 6.7 meters.
Propeller diameter / boat length ratio = 1:43
MODERN CRUISE SHIPS
SAILING BOARDS
SLOOP
CUTTER
KETCH
1. Ketch Speedwell by Flaxbybuck
Length 73.66 cm, (weight ? kg) a three-bladed propeller with a diameter of 35 mm.
Drive type: belt.
Propeller diameter/boat length ratio = 1 : 21.
2. Inga 1V by ChrisG
Length 107 cm, (weight approximately 10 kg) a three-bladed propeller with a diameter of 35 mm.
Transmission type: ?
Propeller diameter/boat length ratio = 1:31
N.B. The model is not yet finished and tested. The manufacturer lets us know that the propeller could be replaced with a larger one if necessary.
SCHOONER
1. AndyN's schooner Valdivia.
Length 142.24 cm, (weight 10 kg) a three-bladed propeller with a diameter of 32 mm (between 30 mm and 35 mm)
Drive type: direct.
Propeller diameter/boat length ratio = 1 : 44 (if 32 mm)
Propeller diameter/boat length ratio = 1 : 41 (if 35 mm)
Propeller diameter/boat length ratio = 1 : 47 (if 30 mm)
Proportions between ship size and propeller diameter
Is it possible to find a very generic rule for sizing the propeller of a model based on the type of ship?
I will re-edit this message whenever there is information to add
There is no doubt that the vast majority of RC naval modelers use the propeller that is supplied in the kit or indicated in the project.
However, it is possible that someone will have to choose it themselves.
As already mentioned, few are looking for the most efficient or most suitable propeller.
I believe that those most interested in the very precise choice, or rather forced by necessity, are the model makers who build fast hulls.
I would like to collect statistics on the models already created.
The first to give us a general indication is Boatshed, according to him:
for a model approximately 45 to 53 cm long, a propeller of 25 mm and above is fine.
for a model approximately 107 cm long, a propeller of 40 mm and above is fine.
Boatshed makes no reference to the weight of the vessel.
It's an excellent start and it's a very valuable indication because it's concrete and pragmatic
For the latest RC naval model in 1/60 scale, 94.5 cm long (excluding the bowsprit) and weighing approximately 5 kg, I used a 40 mm diameter three-bladed plastic propeller.
For the diameter I respected the scale of the time even if the shape was different.
The choice of material and number of blades was dictated only by the fact that it was a very common and cheap propeller.
I am satisfied with the performance and I consciously oversized the choice of engine power.
As regards the number of blades, I believe that the choice is mostly random but it ranges from two to three blades for fast motorboats and from 3 to 4 blades for all the others.
The ratio varies greatly depending on the type of vessel.
__________
TUGS AND WORK BOATS
1 Progress J-502 by Ronald.
Length 38.1 cm, (weight 0.635 kg) a two-bladed nylon propeller with a diameter of 25 mm.
Drive type: ?
Propeller diameter/boat length ratio = 1:15.
2. Miss Katherine tugboat by Ronald.
Length 58.42 cm, (weight 1.54 kg) a three-bladed brass propeller with a diameter of 40 mm.
Drive type: ?
Propeller diameter/boat length ratio = 1:15.
3. Westeriffe by ColinH.
Length 99 cm, (weight 10 kg) a single three-bladed propeller with a diameter of 60 mm.
Gear drive.
Propeller diameter / boat length ratio = 1 : 16.5
4. Ville Class Tugboat by Ronald.
Length 76.2 cm, (weight 3.5 kg) a four-bladed brass propeller with a diameter of 45 mm.
Drive type: ?
Propeller diameter/boat length ratio = 1:17.
5. Zwarte Zee by Wolle.
Length 88.9 cm, (weight 4 kg) a single four-bladed brass propeller with a diameter of 50 mm.
Direct drive.
Propeller diameter/boat length ratio = 1 : 18
(The propeller originally supplied was a three-bladed plastic one)
6. Danny Boy by GaryLC
Length 109.22 cm, (weight ? kg) a five-bladed propeller with a diameter of 60 mm.
Drive type: direct.
true steam propulsion
Propeller diameter/boat length ratio = 1 : 18.
7. Lady Marian of GaryLC
Length 106.68 cm, (weight ? kg) a four-bladed propeller with a diameter of 55 mm.
Drive type: geared.
true steam propulsion
Propeller diameter/boat length ratio = 1 : 19.
8. Oceanic by Wolle.
Length 105 cm, (weight approximately 5 kg), two four-bladed brass propellers, with a diameter of 48 mm.
Ratio between length and diameter = 1 : 22.
9. Rau IX of Wolle.
Length 104 cm, (weight 5 kg), four-bladed plastic propeller, with a diameter of 50 mm.
Drive type: direct.
Ratio between length and diameter = 1 : 21.
FISHING BOATS
1. Highlander Clyde Puffer by GaryLC
Length 86.36 cm, (weight 8 kg) a single four-bladed propeller with a diameter of 55 mm.
Drive type: chain.
Real steam engine.
Propeller diameter/boat length ratio = 1:16
2. Krabbenkutter Tön 12 by Wolle.
Length 50 cm, (weight 2 kg), a three-bladed plastic propeller, with a diameter of 26 mm.
Drive Type: direct.
Ratio between length and diameter = 1 : 19.
PWB and boats of similar features even if with different destination.
1. U.S. Coast Guard PCB, patrol waterways boat Sprinkles by CommodoreH
Length 81.28 cm, (weight kg) two three-bladed propellers with a diameter of 45 mm.
Drive type: geared.
Propeller diameter/boat length ratio = 1 : 18.
2. Sylvie (ex Lotse) by Mike Stoney
Length 53.34 cm, (weight 1 kg) a two-bladed propeller with a diameter of 30 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1 : 18.
RESCUE OR FIRE-FIGHTING BOATS
1. (Fire Boat) Mk2 firefloat 93 by ColinH
Length 86 cm, (weight unknown) a single three-bladed propeller with a diameter of 45 mm.
Drive type: direct.
Propeller diameter / boat length ratio = 1 : 19
2. (Fire Boat) 34" Aerokits Crash Tender by Steven (Fireboat)
Length 86.36 cm, (unknown weight) a single two-bladed propeller with a diameter of 40 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1 : 22
POLICE BOAT
1. Flaxbybuck Sea Queen Police Boat PL502
Length 88.9 cm, (weight ? kg) a two-bladed propeller with a diameter of 45 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1 : 20
LIFE BOAT
1. City of Sheffield by Rogal118
Length 111,76 cm, (weight ? kg) a Two four-bladed propellers with a diameter of 45 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1 : 25
PLEASURE CABIN MOTORBOATS
1. Fairey Huntsman by ColinH
Length 83.82 cm, (weight unknown) a single two-bladed propeller with a diameter of 35 mm.
Drive type: geared.
Propeller diameter/boat length ratio = 1 : 24.
2. Sea scout by ColinH
Length 60.96 cm, (weight unknown) a single two-bladed propeller with a diameter of 30 mm.
Drive type: belt.
Propeller diameter/boat length ratio = 1 : 20.
3. MV Caroline by ColinH
Length 142.24 cm, (weight 13 kg) a single four-bladed propeller with a diameter of 75 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1 : 19.
4. Felix from Flaxbybuck
Length 63.5 cm, (weight ? kg) a two-bladed propeller with a diameter of 30 mm.
Drive type: direct
Propeller diameter/boat length ratio = 1 : 21
5. Sea Queen by Flaxbybuck
Length 116.84 cm, (weight ? kg) a two-bladed propeller with a diameter of 45 mm.
Drive type: direct
Propeller diameter/boat length ratio = 1:26
6. Midwest Cranberry Isle by Ronald.
Length 76.2 cm, (weight 2.7 kg) a three-bladed nylon propeller with a diameter of 42 mm.
Drive type: ?
Propeller diameter/boat length ratio = 1 : 18.
7. Saint Pierre Dory by Ronald.
Length 63.5 cm, (weight 1.63 kg) a two-bladed nylon propeller with a diameter of 28 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1:23.
FAST MOTORBOATS (SLIM SHAPE LIKE THE TYPHOON)
1. Typhoon by River Rat.
Length 101.6 cm, (weight ? kg) a three-bladed propeller with a diameter of 35 mm (or 37 mm).
Drive type: direct.
Propeller diameter/boat length ratio = 1 : 29 (or 1:27).
2. 1930 Chris craft runabout (Driftwood) by River Rat
Length 91.44 cm, (weight ? kg) a three-bladed propeller with a diameter of 35 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1:26.
FERRY
1. Caltex Lumba Lumba di Jumpugly.
Lunghezza 100,33 cm (lungo fuori tutto), (peso 3 – 3,5 kg), una sola elica in Nylon del diametro di 30 mm.
Rapporto diametro elica/lunghezza barca = 1 : 33
OIL TANKERS
1. Deutschland Esso oil tanker by JockScott.
Length 174 cm, (estimated weight 32 kg) a single four-bladed propeller with a diameter of 50 mm.
Propeller diameter/boat length ratio = 1:35
CARGO SHIPS
MODERN WARSHIPS
1. Asheville class gunboat DEFIANCE by CommodoreH
Length 152.4 cm, (weight unknown) double helix with a diameter of 45 mm.
Drive type: belt.
Propeller diameter/boat length ratio = 1:34
2. Italian missile launcher "Caio Duilio"
True ship length 152.9 meters, two propellers, true propeller diameter 4.8 meters.
Propeller diameter / boat length ratio = 1:32
3. Italian frigate "Virginio Fasan"
True ship length 144.7 meters, two propellers, true propeller diameter 4.8 meters.
Propeller diameter / boat length ratio = 1:30
4. USS Arleigh Burke (DDG 51)
Length 153.9 metres, two five-bladed propellers with variable pitch and a diameter of 5.18 metres.
Real ship, not a model.
Propeller diameter/boat length ratio = 1:30.
SECOND WORLD WAR WARSHIPS
(The number of propellers must always be taken into consideration)
BATTLESHIP
1. Italian battleship Roma
Effective length of the vessel 240.7 meters, four propellers, true diameter of two propellers 4.5 meters in diameter and two propellers 4.6 meters.
Propeller diameter/boat length ratio = 1:52
2. German battleship Bismark.
True ship length 251 meters, three propellers, true propeller diameter 4.7 meters.
Propeller diameter / boat length ratio = 1:53
TOWN-CLASS LIGHT CRUISER
1. HMS Belfast C35 Graupner by Scratchbuilder.
Length 124.46 cm, (weight ? kg) four 3-bladed propellers with a diameter of 25 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1:50.
DESTROYERS
1. USS Fletcher of Toradog.
Length 238.76 cm, (weight 30 kg) two three-bladed propellers with a diameter of 75 mm.
Transmission: Direct.
Propeller diameter/boat length ratio = 1:32.
1. Schnellboat by Scratchbuilder.
Length 99.06 cm, (weight ? kg) two three-bladed propellers with a diameter of 30 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1:33.
2. Vosper MBT by Ronald.
Length 63.5 cm, (weight 1.45 kg) a three-bladed nylon propeller with a diameter of 25 mm.
Drive type: ?.
Propeller diameter/boat length ratio = 1:25.
3. MAS 562 (Motoscafo Armato Silurante) by Roy (CB90).
Length 75 cm, (weight) two three-bladed plastic propellers with a diameter of 35 mm.
Driving type: direct.
Propeller diameter/boat length ratio = 1 : 21.
FLOWER-CLASS CORVETTE
1. HMS Buttercup K193 by Scratchbuilder.
Length 86.36 cm, (weight kg) a three-bladed propeller with a diameter of 40 mm.
Drive type: direct.
Propeller diameter/boat length ratio = 1 : 22
2. RMS Titanic by another model maker not from this forum.
Length 72 cm, (approximate weight 3.5 kg) three propellers with a diameter of 20 mm.
Drive type: gear.
Propeller diameter/boat length ratio = 1:36.
2. Queen Elizabeth 2
True ship length 294 meters, two propellers, true propeller diameter 6.7 meters.
Propeller diameter / boat length ratio = 1:43
MODERN CRUISE SHIPS
SAILING BOARDS
SLOOP
CUTTER
KETCH
1. Ketch Speedwell by Flaxbybuck
Length 73.66 cm, (weight ? kg) a three-bladed propeller with a diameter of 35 mm.
Drive type: belt.
Propeller diameter/boat length ratio = 1 : 21.
2. Inga 1V by ChrisG
Length 107 cm, (weight approximately 10 kg) a three-bladed propeller with a diameter of 35 mm.
Transmission type: ?
Propeller diameter/boat length ratio = 1:31
N.B. The model is not yet finished and tested. The manufacturer lets us know that the propeller could be replaced with a larger one if necessary.
SCHOONER
1. AndyN's schooner Valdivia.
Length 142.24 cm, (weight 10 kg) a three-bladed propeller with a diameter of 32 mm (between 30 mm and 35 mm)
Drive type: direct.
Propeller diameter/boat length ratio = 1 : 44 (if 32 mm)
Propeller diameter/boat length ratio = 1 : 41 (if 35 mm)
Propeller diameter/boat length ratio = 1 : 47 (if 30 mm)