CT Only: Supplement 7 Express Boat Tender

[Sir Brad]

actually if you stager them in tight (point one tail up the other down) you can overlap the hulls in the bay, and fit them in better.

 

[snrdg082102]

Evening Hans Rancke,

What's the volume of the bay? That is, how much waste space is there?


Hans

Supplement 7 page 11 "It measures 40 meters by 28.5 meters by 12 meters; this 12 meter dimension can be expanded to 24 meters through the simple expedient of leaving the ship bay doors open. Any ship or group of ships that can meet this dimensional requirement, up to a total of 600 tons, can be carried by the tender through jump space."

Without the lift shaft and the observation platform the dimensions are 40 meters x 30 meters x 12 meters. The lift shaft takes up 1.5 meters on the left side of the diagram and the observation platform takes another 1.5 meters. At the 20 meter mark of the 40 meters the ship/vehicle bay's measurement is 27 meters.

Using the dimensions of 40 meters by 28.5 meters by 12 meters the volume is 13,680 cubic meters. Using the dimensions of 40 meters by 27 meters by 12 meters the volume is 12,960 cubic meters.

I have gotten the sudden feeling I'm lost out in left field and I'll stop with the information I've provided.

 

[rancke]

actually if you stager them in tight (point one tail up the other down) you can overlap the hulls in the bay, and fit them in better.

But you still can't carry them at 100T per boat, can you? It has to be something more than that. The only way to carry them at 100T is to do so in cone-shaped bays (with cupolas to close the bays).


Hans

 

[snrdg082102]

Thank you inexorabletash for the quick response and may I ask what application you are using for the drawings.

Assuming a wedge-shaped Type S that conforms to the description (and makes the actual deck plans nonsensical, of course)...

I originally didn't have the ships rotated in the "plan" (overhead) view. The side view shows that even if you don't offset the ships they can stack directly above each other, although you're probably going to bump turrets if you try that. But there's enough room to rotate the ships, since they're not quite triangular, and if you do that it becomes... quite roomy - nearly all of the exterior hulls would be accessible for inspection and repairs.

Using your work as a guide I too was able to fit two Type S hulls in the bay. I'm probably looking at the last diagram showing the 12 meter dimension correctly, but wouldn't the one flipped in the opposite direction be showing more of a bow shot?

 

[inexorabletash]

what application you are using for the drawings.

"Gimp" which is a free and capable pixel manipulation app like Photoshop, sadly designed by people with really poor user interface skills. Deck plans should really be done in a vector art program; I haven't found one I liked since MacDraw circa 1986.

wouldn't the one flipped in the opposite direction be showing more of a bow shot?

Yes, but I was just manipulating images from scans of Supplement 7. I had to create the side views, since there were none present in the book, but didn't bother creating the bow view.

 

[inexorabletash]

Using the dimensions of 40 meters by 28.5 meters by 12 meters the volume is 13,680 cubic meters. Using the dimensions of 40 meters by 27 meters by 12 meters the volume is 12,960 cubic meters.

And the volume of a 100dTon ship (Type S or X) is ~1400 cubic meters. As the blender mashes, that's room for 9 of 'em in the tender, meaning 4 x-boats take up under half the actual volume, and 2 scouts take up only a quarter of the volume.

And yes, there might be other arrangements, e.g. with overlapping tails, that provide more usable leftover space in the bay. The plans above were just existence-proofs of fitting the ships in.

But you still can't carry them at 100T per boat, can you? It has to be something more than that. The only way to carry them at 100T is to do so in cone-shaped bays (with cupolas to close the bays).

Not sure what you're asking... they obviously fit, so are you pondering how they are kept in position during maneuvers? Since a load out of the ships 4-up/2-up is apparently common practice, I'd assume the three ship designs have explicitly designed and matching lock-downs/hard-points on the hulls/bay for precisely this. Scouts are probably trained in getting the ships secured in the bay well enough to do it blindfolded by the end of their first term, and under fire/during evasive maneuvers by the second term.

 

[rancke]

Not sure what you're asking... they obviously fit, so are you pondering how they are kept in position during maneuvers?

No, I'm wondering how many dT of water the bay will hold. The X-boats would displace 4x100 dT of water, but there is room for more in between them. That figure, whatever it is, is the space the bay takes up out of the tender's total tonnage. So if you have a 1000T tender, 500T¹ (not 400) is used to carry those X-boats, leaving 500T¹ (not 600) for the drives and fuel tanks and accomodations and bridge and computer and whatnot.

¹ Or whatever the figure is.​

Hans

 

[snrdg082102]

Afternoon inexorabletash,

"Gimp" which is a free and capable pixel manipulation app like Photoshop, sadly designed by people with really poor user interface skills. Deck plans should really be done in a vector art program; I haven't found one I liked since MacDraw circa 1986.

Thank you for the application name. The free part is within my current budget, but the user interface may a deal breaker. I'll have to think about this a bit more.

Yes, but I was just manipulating images from scans of Supplement 7. I had to create the side views, since there were none present in the book, but didn't bother creating the bow view.

Yippee, I'm not as far out in left field as I thought.

 

[snrdg082102]

Hello inexorabletash and Hans,

And the volume of a 100dTon ship (Type S or X) is ~1400 cubic meters. As the blender mashes, that's room for 9 of 'em in the tender, meaning 4 x-boats take up under half the actual volume, and 2 scouts take up only a quarter of the volume.

I was right inexorabletash about being out in left field which met I lost track of where I was heading trying to reply to Hans in post 22. Unfortunately, Supplement 7 page 11 limits the ship/vehicle bay to 600 tons, which I take to be with the bay doors shut. This limit I also take to be the limit of what can be transported through jump space and also the space needed to perform maintenance on the x-boats or scout/couriers.

However, we also have to take into consideration that the number of hulls have to fit within the physical dimensions of the bay. Looking at the deck plans presented in the thread I can't visualized fitting nine x-boats or four scout/couriers in the physical dimensions. Heck, without your help I wouldn't have figured out how t stuff the four and two discussed in Supplement 7.

And yes, there might be other arrangements, e.g. with overlapping tails, that provide more usable leftover space in the bay. The plans above were just existence-proofs of fitting the ships in.

My efforts showed arrangements that didn't work out to well.

Not sure what you're asking... they obviously fit, so are you pondering how they are kept in position during maneuvers?

No, I'm wondering how many dT of water the bay will hold. The X-boats would displace 4x100 dT of water, but there is room for more in between them. That figure, whatever it is, is the space the bay takes up out of the tender's total tonnage. So if you have a 1000T tender, 500T¹ (not 400) is used to carry those X-boats, leaving 500T¹ (not 600) for the drives and fuel tanks and accommodations and bridge and computer and whatnot.

¹ Or whatever the figure is.​

Hans

Hans, I may be on the wrong track but here is my attempt at answering.

So far my numbers have the bridge/accommodation deck, fuel tankage, and drive deck taking up 281 tons of the 1,000 ton hull. A full cargo deck per Supplement 7 page 12 stores 60 tons and per Supplement 7 the ship/vehicle bay holds a maximum of 600-tons.

Provided my calculation are right I still have 59-tons of unused space. Looking at the Captain's Cabin (17) and the area with the digits of 16 I see where some of the 59 tons can be applied to.

When the ship is carrying a full load of cargo and 4 x 100-ton express boats they use 460 tons of the hull's space leaving 540 tons for drives, fuel, bridge, and accommodations. Putting a 600-ton hull in the bay and having a full load out of leaves 340 tons for something else.

I'm not really sure I'm on the right track so I'm stopping the train before I'm really lost.

 

[rancke]

It should be easy enough to figure out the actual¹ volume of the bay in inexorabletash's drawing, except that the lines are very faint². I was hoping that Inex, if I may abbreviate his monicker thus, would be able to provide the information with no further ado.

¹ Not what the rules say, but what plain simple spatial geometry says.
² Especially if you ignore the halfcircles and rounded corners.​

Hans

 

[inexorabletash]

It should be easy enough to figure out the actual volume of the bay in inexorabletash's drawing, except that the lines are very faint.

Ignoring the rounded corners and the observation deck area, it's nominally 26x18x8 squares in the drawings with 1.5m squares, or 39m x 27m x 12m.

Within the accuracy of the drawing this matches the dimensions are as given in Supp 7, slightly on the smaller side:

Supplement 7 page 11 "It measures 40 meters by 28.5 meters by 12 meters"

That's 13,680 cubic meters, or 1000dtons, which is obviously larger than the 600dtons listed for bay capacity (and 1000dtons is the ship's overall displacement tonnage). So... yes, someone's being sneaky and saying that somehow they can get away with counting a 1000dton volume as 600 dtons for ship design purposes for if you promise you never fully load it.

 

[Carlobrand]

As described in Supplement 7, the tender's total volume is 19,746 cubic meters, or 1462.67 dTons. Given the dimensions of the express boat, it's difficult to modify the dimensions and keep the bit about being able to hold 4 x-boats.

 

[rancke]

That's 13,680 cubic meters, or 1000dtons, which is obviously larger than the 600dtons listed for bay capacity (and 1000dtons is the ship's overall displacement tonnage). So... yes, someone's being sneaky and saying that somehow they can get away with counting a 1000dton volume as 600 dtons for ship design purposes for if you promise you never fully load it.

It sounds like someone is being rules-lawyeringly oblivious of reality. That's just what I surmised would be the case. Even so, I'm surprised that the required tonnage is that much bigger. We're talking 1000T to carry 400T, or 250% of volume. That's more than the 200% employed in the rule for carrying craft in empty weapons bays.

Can you fit the necessary drives, accomodation, and fuel tankage into a 1400T design with a 1000T bay? If so, that seems the best fix, keeping the deck plan but changing the statistics. Perhaps one could even make it a 1500T design, relying on the "10% slop" rule of deck plan drawing. Otherwise, a complete redesign seems indicated, with actual customized cone-shaped 100T bays designed to hold X-boats and nothing but X-boats.


Hans

 

[Patron Zero]

Mind no naval architect here but wonder if the X-boats being serviced or transported might be better served in individual 'silos' than the open bay design of the original tender ?

Essentially a new design that might outwardly appear as compound hull design of a central rectangular 'core' containing the essentials of drives, fuel tankage, crew accommodations etc and four (4) separate maintenance-repair cylindrical 'silos' that are adjacent to the central section.

Mind this new configuration would likely not be streamlined, much more a utilitarian appearance than the classic tender design with it's various work-arms and docking frames clearly seen. That said, fuel-skimming of gas giants would be a task for streamlined drones freeing the entire vessel to other labors less mundane.

Said 'silos' would be skeletal structures, open frameworks capable of being made pressure-capable work-bays after a temporary 'skin' of plastic-metal panels are so assembled around such. I picture two (2) separate 'silos' set between a central 'gantry-crane', such arrangement aside two sides of the central 'core' of the tender proving berthing and service space for a total of four (4) separate X-boats.

I would imagine with some tweaking of the proposed design that scout-couriers could also be included in regards to bay-berthing but the initial concept is specifically for X-boat support-transfer.

http://www.travellerrpg.com/CotI/Gallery/images/8640/large/1_tender-transport_logo.jpg

 

[Carlobrand]

Let's begin with: this is one messed up ship. First, even with the errata I can't make it add up; I get 4 dT extra space unaccounted for. Second, it's using larger and more expensive H drives when the size calls for E drives. The larger engine demands a third engineer, when the E drives would need only two. And, as I mentioned, the deck plan is oversize by 46%.

My best rendition of four X-boats stacked comes to 640 dTons and leaves no way to get from the bridge to the engine room. You have to move the bridge deck and cargo deck back so they're inter-accessible without needing that side corridor down one side of the bay, and then you can cut length or width to bring the ship down to ~1000 dT. There's a lot of wasted space implicit in trying to stack four ice cream cones in a carton like this. X-boat's a cool shape, but it wasn't designed for stacking.

Salvaging this particular ship requires you to re-envision the ship as a dispersed structure tender. Lose the bay doors and open the bay to space so you don't have to enclose the entire bay in a jump field, and your ship becomes a 1000 dT tender docking four 100 dT ships, instead of a 1400 dT transport with an 800 dT bay that contains those four ships.

 

[mike wightman]

Are you truing to match the design with '77 LBB2 or '81 revised?
In 77 the smallest drive you can put in a 1000t hull is the H, the drive potential table was changed for '81.

S7 designs are 77 LBB2, plus the unknown GDW ship construction house rules that allow the Gazelle to exist.

 

[aramis]

Are you truing to match the design with '77 LBB2 or '81 revised?
In 77 the smallest drive you can put in a 1000t hull is the H, the drive potential table was changed for '81.

S7 designs are 77 LBB2, plus the unknown GDW ship construction house rules that allow the Gazelle to exist.

There are several missing components... like the data banks on the XBoat, the pop-turrets on the tender, the barbettes on the Gazelle and SDB...

 

[snrdg082102]

Howdy inexorabletash,

Ignoring the rounded corners and the observation deck area, it's nominally 26x18x8 squares in the drawings with 1.5m squares, or 39m x 27m x 12m.

Within the accuracy of the drawing this matches the dimensions are as given in Supp 7, slightly on the smaller side:



That's 13,680 cubic meters, or 1000dtons, which is obviously larger than the 600dtons listed for bay capacity (and 1000dtons is the ship's overall displacement tonnage). So... yes, someone's being sneaky and saying that somehow they can get away with counting a 1000dton volume as 600 dtons for ship design purposes for if you promise you never fully load it.

Even with the slop factor that the drawing deck plans allow for your right someone pulled a fast one.

 

[HG_B]

There are several missing components... like the data banks on the XBoat, the pop-turrets on the tender, the barbettes on the Gazelle and SDB...

The one thing I always thought strange was the need for a pop-turret on a gov ship of a standard, widespread design. It ins't like it has to hide the weapon from authorities or, that it doesn't become generally known so as to obviate any surprise factor.

 

[snrdg082102]

Hello again Carlobrand,

The smallest drive letter for a 1,000 ton vessel under Book 2 1st editions rules is type H. Using Book 2 2nd edition you are correct the smallest drive letter is E.

I'm getting the impression that many of the Supplement 7 designs used the first edition of Book 2.

Drat, Mike Wightman beat to the answer, sorry about being redundant, okay redundant as usual.

Let's begin with: this is one messed up ship. First, even with the errata I can't make it add up; I get 4 dT extra space unaccounted for. Second, it's using larger and more expensive H drives when the size calls for E drives. The larger engine demands a third engineer, when the E drives would need only two. And, as I mentioned, the deck plan is oversize by 46%.

My best rendition of four X-boats stacked comes to 640 dTons and leaves no way to get from the bridge to the engine room. You have to move the bridge deck and cargo deck back so they're inter-accessible without needing that side corridor down one side of the bay, and then you can cut length or width to bring the ship down to ~1000 dT. There's a lot of wasted space implicit in trying to stack four ice cream cones in a carton like this. X-boat's a cool shape, but it wasn't designed for stacking.

Salvaging this particular ship requires you to re-envision the ship as a dispersed structure tender. Lose the bay doors and open the bay to space so you don't have to enclose the entire bay in a jump field, and your ship becomes a 1000 dT tender docking four 100 dT ships, instead of a 1400 dT transport with an 800 dT bay that contains those four ships.