Deck orientation

[TheColonel]

Here is a hardcore design question. What size of ship do you see decks being vertical to the thurst plates versus horizontal? I think that there are far too many ships that keep the inefficent horizontal orientation. It is eaiser to design and draw plans horizontally but it makes far greater sense for verical orientation on anything bigger than 1000 tons. This opinion is definiately true for any space only craft.

A large ship with a 1G drive would need almost no artifical grav since it could be constantly thrust at 1G on a interplantary voyage. Any thoughts?

 

[Uncle Bob]

I have got to agree. That is why the Azhanti High Lightning blew me away. Horizontal deckplans make some sense for vessels that will be ding a lot of atmospheric maneuvering, but not for large, or even middle-sized ships.

My own deck plans tend to conform.
http://pages.sbcglobal.net/blyle/Deckplans.htm

 

[TheColonel]

very efficent design.

 

[gardclan]

There are definite advantages to going with either method. Decks which are parallel to the thrust axis are better for slim or flat profile ships or vessels which will be using airframe hulls.

Large ships or ships with broad cross sections (such as Uncle Bob's clipper) can make due just fine with their decks arrayed perpendicular to the axis of thrust. Besides, larger ships have an easier time getting all of the decks plotted out on reasonable paper sizes if they have many perpendicular decks as opposed to a few parallel ones. Not only that, but it is much easier to compartmentalize the hull because the decks form transverse bulkheads.

So, I think this is more a function of hull form and purpose of the craft than it is a function of craft size. For example, the classical Broadsword has perpendicular decks, but the Kinunir (not very much larger on the HG scale of things) has parallel decks. Perpendicular decks wouldn't work quite as well with the kinunir due to its shape.

As a side note, I don't necessarily think that perpendicular decks would be restricted to space only craft. Uncle Bob's homage to the delta clipper should have relatively few problems landing on a planet if its thrusters are configured properly.

IIRC The real Delta Clipper is supposed to be a single stage to orbit vehicle prototype, and is arranged in a similar fashion (although much smaller.)

 

[Uncle Bob]

The DC-X was smaller, but the proposed "Delta Clipper" was the big orbital transport and a good deal bigger evan than my Clipper.

It was proposed that the Delta Clipper could also be refueled in orbit and used as a Lunar transport.

Close, though. Thank you.

 

[Tom Schoene]

Originally posted by Uncle Bob:
The DC-X was smaller, but the proposed "Delta Clipper" was the big orbital transport and a good deal bigger evan than my Clipper.

Do you have a good source for info on the full-size Delta Clipper? I did some googling and couldn't find any details on how big it would have been or how much payload it could have carried.

TIA

 

[Uncle Bob]

All my DC links are dead, dammit.

Best I can do is http://www.spacefuture.com/archive/a_cost_engineered_launch_vehicle_for_space_tourism.shtml

That indicates the DC-Y was about 600 tons. IIRC it was about 1/3 scale so the Clipper was supposed to be about 2000 tons.

 

[CaptainJames]

Try this link, its got some information on a number of SSTO proposals.

http://www.astronautix.com/lvfam/vtovl.htm

The Encyclopedia Astronautica is a great source for data on lots of TL6-7 spacecraft.

 

[Mr. Oberon]

Keep in mind, regardless of effectiveness, Humans like (actually, it's more like demand) an effective up and down that matches the movements they are going to make. In other words, people like to feel pushed "back" by increased speed, and like to feel right and left correctly when piloting and "feeling" the ship.

We are terrestrial creatures... We can't help it.

Mr. Oberon
"Devil's advocate"

 

[Uncle Bob]

I can understand that. NASA's love affair with aircraft-style landings (as evidenced by the STS and X-33 program) has crippled the space program for decades.

I like astronautix.com. Another page, less detailed but worth looking at is http://www.spacefuture.com/vehicles/designs.shtml

 

[TheColonel]

Originally posted by MrOberon1972:
Keep in mind, regardless of effectiveness, Humans like (actually, it's more like demand) an effective up and down that matches the movements they are going to make. In other words, people like to feel pushed "back" by increased speed, and like to feel right and left correctly when piloting and "feeling" the ship.

We are terrestrial creatures... We can't help it.

Mr. Oberon
"Devil's advocate"

True, but you can then jsut make the Bridge in that orientation. The rest of the ship could still be oriented like a building. Given the complete lack of feel of the change of direction due to artifical gravity (per different source books) it still wouldn't matter. Of course if artifical grav ever failed in a "horzontal" ship, moving around the ship would be very difficult under any G manuever.

 

[Uncle Bob]

The DC-X is not the Delta Clipper.

The DC-X was supposed to be the little brother to the suborbital DC-Y. The money congress appropriated for the DC-Y was diverted by NASA to the X-33 boondoggle. The Delta Clipper was going to be the orbital verson, three times bigger than the DC-Y.

I was wrong, but the truth is even better. The 2000 ton Delta Clipper would have been about 500 dtons, the same as my Clipper.

 

[Uncle Bob]

Naturally, I can't find most of my notes, including the stuff I got from G Harry Stein back around 1992.

However, this is a NASA image showing the three X-33 proposals, Lockmart, MDAC, and NAR. These were all suborbital vehicles, as the program was defined by Congress to fund the DC-Y and Delta Clipper program.

This is a Boeing/MDAC graphic that compares the MDAC DC-Y/X-33 (white) with the final Delta Clipper (black).

At the time I was looking at mass ratios and thought the DC-Y was close to orbital. The response I got was "hell no," but without payload and with no-one looking I still think it could make LEO.

 

[Uncle Bob]

=4.6^2*pi*46/2=3058 m3
3058/13.5=226 dton, so we were both wrong.

I missed those numbers on the FAQ, but they look reasonable

 

[Uncle Bob]

I yield.

Serves me right for posting half asleep, That gives a RW mass of about 350 tons. With a MR of 10:1, 5% tankage, that leaves a payload of about 10 tons. Good to know.