Ships of Jutland

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Antiquities
Joined: 2013-07-05 19:55
Ships of Jutland

In the Player's Companion, we have the Scandinavian-inspired Jutland barbarians. They need some Scandinavian-inspired ships. The best archeological evidence (that I'm aware of, anyway) are the Skuldelev ships, a number of 11th-century vessels that were sunk to block Roskilde fjord and recovered in the 1960s. The five ships (1-3 and 5-6) were two longships, two merchant vessels, and a small ship that has been suggested was either a ferry or a fishing vessel ("Skuldelev 4" was found to be part of the Dublin-built Skuldelev 2). Using the latest draft of the ship rules I've been working on (some of the development is cataloged at http://www.autarch.co/forums/house-rules/hr-naval-rules), here are two of the smaller ships, waiting for Jutland sailors to take them into action. Some of the stats wouldn't normally be used, but I wanted to keep all of the information in the table.

Skuldelev 3 (small merchant/byrding)
Length: 39 feet
Beam: 8 feet
Draught: 2 feet, 5 inches
Freeboard: 1 foot, 6 inches
Base Seaworthiness: 4
Armor Class: 4
Seaworthiness: 5
Tonnage: 10 tons
Structural Hit Points: 12
Starting capacity: 2,000 stone
1 mast, 2 sails (actually one large sail), square rig
Sailing MP: 5
Sailing crew needed: 4
Crew needed for full rowing speed: 24
Oars: 4
Rowing MP: 1
Capacity: 1,968 stone
Special quality: clinker-built
Cost: 1,520 gp (with oars and one full-size sail)

Skuldelev 5 (small longship/snekkja)
Length: 59 feet
Beam: 8 feet
Draught: 2 feet, 1 inch
Freeboard: 1 foot, 3 inches
Base Seaworthiness: 3
Armor Class: 3
Seaworthiness: 4
Tonnage: 10 tons
Structural Hit Points: 12
Starting Capacity: 2,000 stone
1 mast, 2 sails (large sail), square rig
Sailing MP: 6
Sailing crew needed: 4
Crew needed for full rowing speed: 24
Oars: 24
Rowing MP: 4
Capacity: 1,958 stone
Special quality: clinker-built
Cost: 1,620 gp (with oars and one full-size sail)

Note that while there's little difference between the two in capacity or cost, the merchant ship will have five or six crew, while the longship will have twenty-six to thirty, which will require more supplies and weight for the crew (and the raiders' weapons). Both ships will sail as much as possible, but row in contrary winds.

koewn
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Neat!

Been thinking a lot about ships lately putzing around with making a new venturer stronghold type.

Comparing the Skuldelev 3 to the ACKS Small Galley:

The rowing is a -lot- slower, but sailing is a lot faster - a (rounded) 30/140 as opposed to 60/90, in miles-per-12-hour-day. I've been modeling the galleys based on (12 hours) of rowing & sailing split evenly, so yours averages out a bit faster -85 miles/12h-day rather than 75.

Capacity then is listed independently of *any* crew or their supplies - I believe the ACKS ships have taken crew weight/rations weight into account.

If I figure 10 people - 4 sailors, 4 rowers, 2 merchants - that's 150 stone of people.

The ACKS Small Galley carries 20 marines, or 1 marine per 100 stone. We'd want, then, 8 marines at, say, 20 stone per, for 160 stone of marines.

Weight of supplies for 16 regulars and 4 rowers would be 24 stone per day, if we have to have 28 days of supplies, that's 672 stone (much less if we only stock for the voyage)

That leaves ...986 stone for cargo?

Fixed costs are 84gp/mo for the crew, plus, let's say, 104gp for the supplies (ACKS pegs sea rations at 5gp/mo, plus a bit extra for the rowers)

If I didn't mess this up over my increasingly short lunch hour, the Skuldelev 3 is profitable for most types of routes.

Mostly, this is due to the change in crewing - particularly the rowers. The ACKS Small Galley is showing 60 rowers for a little over twice the cargo capacity.

Even if you cut out all sailing movement, the Skuldelev is much more efficient per rower for cargo moved and still makes a profit on many more routes.

I realize most of this is the paternal heritage that ACKS was drawing from, which is fine. It's also a bigger ship, with two to three times the beam and twice the length, and I don't know how that'd build out in your system.

I'm very excited to see the ship construction rules, and what changes they bring in modeling the ships already present in ACKS. I think this will complement the venturer rules I'm working on *very* well.

Antiquities
Joined: 2013-07-05 19:55

"The rowing is a -lot- slower, but sailing is a lot faster - a (rounded) 30/140 as opposed to 60/90, in miles-per-12-hour-day."
MPs are slightly different in the rules I'm working on. Right now, it's 2 MP per 30 feet per round, assuming fair conditions (a Moderate Breeze for sailing or Gentle Breeze or less for rowing, using the Beaufort scale), so by the main book it's 15'/9 miles rowing or 75'/115 miles sailing, so it would be around 60 miles per 12 hour day by your method. The single rowing MP is also a bit of a compromise. In the previous draft, it wouldn't have been able to row without having at least 12 oarsmen, but given that it only had four rowing stations for single rowers, that obviously wasn't going to work. She'll be heavily weather-dependent (like most sailing ships). In a Moderate Breeze, rowing won't generate any MP, and anything below a Moderate Breeze will see her sailing MP drop off rapidly, so moving against the wind will be difficult.

"Capacity then is listed independently of *any* crew or their supplies - I believe the ACKS ships have taken crew weight/rations weight into account."
They do; I just didn't want to make any extra assumptions yet, and leave them as open as possible for modification.

"Mostly, this is due to the change in crewing - particularly the rowers. The ACKS Small Galley is showing 60 rowers for a little over twice the cargo capacity."
A lot of this does tie back to the heritage, as you mentioned - the Small Galley is actually a rather dreadful cargo ship, and works much better as a light scout/combatant. A kerkouros (merchant galley) of 45 cubits length and 7 cubits width (67.5x10.5 feet) had 20 rowers, and would have had a hold that could carry around 34 tons (6,800 stone), with no allowance for deck cargo or things stuffed into crannies. That was actually a fairly small kerkouros - the Tebtunis Papyri record a monster (of unknown dimensions and rowers, unfortunately) with a rated capacity of 450 tons - and the Oxyrhynchus Papyri have ships with "rated" and "actual" loads, with most of the actuals 10% higher than the ratings!

Both ships are also quite fragile, since I was going with 1 ton = 1 shp (with clinker built adding to that). That puts them down at canoe/lifeboat range, which is too low. I'll probably be adjusting that in the future.

Antiquities
Joined: 2013-07-05 19:55

On the fragility front:

There have been a few different ways suggested to calculate shp.

The first one that I used was the 1 ton per 1 shp, which was how the base shp for the ships was calculated. That gave us 10 (modified to 12 by clinker) for shp.

The second one is from http://www.autarch.co/blog/domains-war-designers-notes-2-sieges, where it was said that an estimate for a "wooden structure" would be 1 shp per 80 gp. The hulls of these two ships cost 1200 gp each, which would put them at 150 shp each. That's obviously too much, since the War Galley is only 125-150 shp.

So, naturally, I decided on a third way. I took each of the ships described in the main book except the raft and troop transports (which are modified sailing ships). For each, I took their minimum size (for a river boat, 20x10x2) and their maximum size (again, for a river boat, 30x15x3), calculated tonnage (using Builder's Old Measurement), assigned minimum shp to the small, maximum shp to the large, found the shp per ton, and took the average. It came out to 4.5 shp per ton across all ships, ranging from 0.4 for the largest of the Large Sailing Ships to 23.5 for the Canoe (must be a dragonhide canoe...). Taking out the Canoe and Lifeboat as outliers, the average dropped to 2.9 shp per ton, so I will likely use 3 shp per ton as my standard going forward.

Antiquities
Joined: 2013-07-05 19:55

I just thought of this. Here's the shp range for each class of ship from the ACKS core book if they're calculated at 3 shp/ton (with some rounding):

Boat, River: 10-30
Boat, Sailing: 10-45
Canoe: 1
Galley, Large: 160-265
Galley, Small: 35-130
Galley, War: 275-760
Lifeboat: 4
Longship: 35-100
Sailing Ship, Large: 680-1520
Sailing Ship, Small: 150-475

Small ships become quite a bit weaker, and large ships much stronger. Given the history of ship combat, I'm OK with that, but your mileage may vary (after all, this is still a house rule).

Tom Hudson
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Joined: 2011-07-24 18:35

Math error? 1200 / 80 = 15

Antiquities
Joined: 2013-07-05 19:55

Either math error or mental moment. I think when I did the math, I flipped back to check the statement, and accidentally used the number for stone (8 gp = 1 shp), but left the number for wood in the comment. So yes, they would be 15. That's too little in my mind, since riverboats are still 133%-300% of that number.

koewn
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Interesting.

Given the scope of what you're doing and the...dearth of scope in D&D in general for ships and ship warfare treating your thing here as a drop-in replacement for ACKS or related game is probably not a bad way to go.

My excitement prepping that ship out as a merchant was my short-lived quest to find something speedy to do against-the-current river trade with. I'm not getting a lot of results. The Nile evidently had a special case of having consistent favorable prevailing winds from the north, but I'm not getting a lot of other concrete results (may be looking in the wrong spots).

Even up till the steamboat era trade on the Mississippi was in some part one way - float barges down to New Orleans, walk back. In other places there was towpathing, with a horse drawing a barge, but that somewhat requires infrastructure in the towpaths and possible canals.

I may just end up using a rower-less galley and cutting the speed down (averaging a high with-current speed against a very low against-current speed) to represent tacking against the wind on the way back - a larger ACKS river boat, in essence.