04192021, 01:01 PM  #1 
Join Date: Aug 2004
Location: Ronkonkoma, NY

Vehicles, range, fatigue
Unpowered vehicles rowed or pulled by beings have Range F, which means the FP of the rowers or pullers and their provisions limit range.
Is there anywhere in the rules that FP costs for rowing or pulling? How many men do I really need to keep my 30oar longship moving up the river without halting? How far will my wagon drawn by two horses really go before resting? "Rowing is kind of like hiking" is an unsatisfying answer. 
04192021, 01:32 PM  #2  
Join Date: Aug 2004
Location: Wellington, NZ

Re: Vehicles, range, fatigue
Quote:
Now, what's lacking are detailed rules for speed vs FP consumption. The best we get is that ~75% of top speed is like hiking, and thus can be continued until the sleep rules take the rowers out of action, and that top speed uses FP like running does and thus costs 1FP per failed HT roll (presumably you could substitute Boating (Unpowered) for HT), rolling once per minute. This is actually pretty good for professional oarsmen  they'll have HT/Boating at 12 or so, and even with the normal 10FP can spend 7FP before speed drops to 1/2, and thus will be rowing at top speed for nearly 30 minutes, on average. I'd consider ruling that FP is spent as sprinting (i.e. four times as fast), or make some more detailed rules that allow for 'hiking', 'running', and 'sprinting' speeds.
__________________
Rupert Boleyn "A pessimist is an optimist with a sense of history." 

04192021, 01:44 PM  #3 
Join Date: Jul 2008

Re: Vehicles, range, fatigue
I'll add that what Rupert is saying is on Campaigns p463
__________________
I don't know any 3e, so there is no chance that I am talking about 3e rules by accident. 
04192021, 02:53 PM  #4 
Join Date: Aug 2004
Location: Ronkonkoma, NY

Re: Vehicles, range, fatigue
Ah, okay, the rule I was looking for is in the section on Cruising Speed. Thanks.

04212021, 05:12 AM  #5 
Join Date: Aug 2004
Location: Helsinki, Finland

Re: Vehicles, range, fatigue
Speaking of rowed watercraft with multiple rowers, when you have less than a full compliment, how much would you reduce the speeds that the vessel can achieve?
I mean, you could just call it that with 50% of rowers you can achieve no more than 50% of the top speed, but does anyone have a better idea? It's been too long since I last rowed a boat with multiple rowing positions to remember how it was affected.
__________________
[/delurk] AotA is of course IMHO, YMMV. vincit qui se vincit 
04212021, 06:35 AM  #6 
Join Date: Oct 2010
Location: Cambridge, UK

Re: Vehicles, range, fatigue
At constant speed, thrust from rowers is equal to drag. And drag is proportional to velocity squared. So if you halve the number of rowers, you divide speed by sqrt(2).
__________________
The Path of Cunning. Indexes: DFRPG Characters, Advantage of the Week, Disadvantage of the Week, Skill of the Week, Techniques. 
04212021, 09:02 AM  #7  
Join Date: Jun 2013

Re: Vehicles, range, fatigue
Quote:
Quote:
Step 1) Divide the weight of the vessel by its length in yards. That value works asis for rafts and square barges; for a vessel with rounded lines, multiply by 0.7; for a vessel with long lines, multiply by 0.5. This is "effective weight" (eW). Step 2) (poling/rowing only) Combine the BL's of all polers/rowers. For poling (and paddling, basically any "arm only" option), use 30xBL for sustained poling (functioning similarly to Hiking), 70xBL for more rapid poling (comparable to Jogging), and 150xBL for fullspeed (comparable to Sprinting). For rowing, these values are instead 50xBL, 100xBL, and 200xBL, respectively. The end result is "power" (P). Step 3) For towing, use eW multiplied by Move squared as encumbrance (spread out over all characters/creatures involved). For poling/rowing, divide P by eW, then take the cube root of the result to determine maximum Move. That is: Towing: eW * Move^2 = encumbrance Poling/Rowing: (P/eW)^(1/3) = Move In all cases, Move is relative to the flow rate of the body of water. If you need to tow a vessel on a river, subtract the flow rate from Move before squaring it if traveling downstream, add the flow rate to Move before squaring it if traveling upstream. If you need to pole/row a vessel on a river, add the flow rate to the determined maximum Move if traveling downstream, subtract it if traveling upstream. As an example, let's take a 10yard raft, and load it up to 1000 lb (including its own weight; note I'm just pulling numbers out of the air, here). It has an eW of 100 lb (1000/10). Towing it at relative Move 1 reduces the halfton load to 100 lb  with 5 people of average ST, they'd each be right at Light Encumbrance (20 lb), and could comfortably move at Hiking speed. Towing it at a relative Move 2 means that halfton load is instead 400 lb (multiply by 2^2), meaning either ExtraHeavy Encumbrance (and the characters cannot get up to Move 2 anyway; they might be at this level if towing upstream, however) or needing more people (or stronger animals) doing the towing. (EDIT: Also, note that in this case, if you need to move much faster than 3 yards/second relative to flow rate, you're better off just carrying it  the breakeven point is the square root of 10, or around 3.16) Five people poling or rowing it means a combined BL of 100. Poling at a "hiking" rate means a P of 3000 (30x100), a P/eW of 30, and thus a maximum Move of 3.1 (cube root of 30). Poling at a "jogging" rate means a P of 7000, a P/eW of 70, and maximum Move of 4.1. Poling at a "sprinting" rate gives a P of 15000, a P/eW of 150, and a maximum Move of 5.3. For rowing, the maximum Moves are 3.7, 4.6, and 5.8, respectively.
__________________
GURPS Overhaul Last edited by Varyon; 04212021 at 09:10 AM. 

04212021, 10:27 AM  #8  
Join Date: Feb 2005
Location: Berkeley, CA

Re: Vehicles, range, fatigue
Quote:
In reality, neither constant thrust nor constant power is an accurate model, nor is drag coefficient constant, so while you can assume that fewer rowers is slower, how much slower is difficult to determine. 

04212021, 09:24 PM  #9  
Join Date: Aug 2004
Location: Wellington, NZ

Re: Vehicles, range, fatigue
Quote:
Though, when I was trying to work out real life battleship ranges to get fuel consumptions, and wanted an estimate of their ranges all at the same speed, I found that the numbers came out all over the place, but seemed to average about a 2.5 power. One of the problems is that engines (and oarsmen) have an optimal output and lose efficiency outside that, in some cases enormously. Another is that ships have several sources of drag, and they scale differently with speed, and some matter more at low speeds, others at high speeds. To make matters worse, just how they scale and which one matters more depends on the size and shape of the ship, not just the speed. TL;DR Ship performance is very complicated.
__________________
Rupert Boleyn "A pessimist is an optimist with a sense of history." 

Tags 
boats, speed 
Thread Tools  
Display Modes  

