Maybe this is more a question for the Rogue Trader forum, but it came up in our DH campaign. So, sorry if it is misplaced:

The party of Akolythes in our campaign captured a small transport ship in one of our last adventures. And "small" means "small", that is 40-50 metres following the description in the adventure (which I loaded down from the FFG page, if I remember it correctly). Regarding to the adventure this ship was capable of interstellar flight. Our Akolythes decided to keep the ship for their personal use at the end of the adventure. Some of them have the necessary skills. In the end I decided to let them keep it.

But later the question started: Is a ship of that size really capable of interstellar flight in the WH40k universe even with a Navigator? The Lexicanum says that the Viper Class Scout Sloop is "among the smalles Imperial starships capable of carrying a warp drive". And the Sloop is definitly bigger than our transport. Most ships in the WH40 universe are hundreds of metres long, often kilometres and have thousands of crew members. On the other hand one can read in some novels like Eisenhorn or Ravenor about small yacht like ships, which are capable of warp flight.

So... can there be starships of that size with a warp drive in "our" WH40k universe? Or would it be better to specify the transport ship as an innersystem spaceship which needs to be transported by bigger interstellar vessels to other star systems?

Unfortunately with just about everything in WH40K it depends, and varies depending on who is currently writing.

I think Eldar have small ships capable of warp travel, I think the Rangers use them. Not sure, not an Eldar man myself.

Some organisations have access to the capability like the Inquisition but it's incredibly rare. I would say it's more likely that the ship would be interplanetary.

One option would be to rule that the ship has a 'two-stage' design: the part the PCs control is used for transport to and from orbit; in orbit, it hooks up to the main body of the ship (which isn't landing-capable), which contains the warp drive.

Amberly Veil had a warp capable yacht, so the answer is definitely yes. It is rare to have warp capable ships come in smaller sizes, but with xenos, archeo, and other forms of technology present in the 40k universe, it's quite possible, just improbable to come across by the average citizen or soldier of the Imperium.

Thanks guys for the answers. I agree with you: There are small warp capable ships. But our Akolythes are definitly not among those, who have access to such rare vessels. So our ship will be an interplenetary vessel without warp capability and it has to be transported by bigger ships to other star systems.

It's far more possible to have a small interplanetary ship and requisition/buy/demand interstellar passage on a passing trading vessel like Ravenor and Eisenhorn do.

I was under the impression that Abnett's books are highly controversial (despite their popularity) as clashing with the setting as depicted everywhere else.

I personally would say "no." This is Age of Sail in space. You can't have a transoceanic rowboat.

Rogue trader gives some stats on ships in the main book that may work

"This is Age of Sail in space. You can't have a transoceanic rowboat."

This is a very nice quote @ bogi_khaosa

Also note that there is a difference between "interstellar" and "warp-driven." You could quite easily have a small subwarp vessel that puts its crew into stasis for the projected few months/years that it'll take to reach the next nearest system.

Also note that there is a difference between "interstellar" and "warp-driven." You could quite easily have a small subwarp vessel that puts its crew into stasis for the projected few months/years that it'll take to reach the next nearest system.

Decades.

And those ships would likely be quite large, as you'd need to store fuel for the entire (long) trip.

I know this is just a game, otherwise you'd expect that with an initial velocity of the spacecraft and encountering no actual resistance to slow the vessel down, you wouldn't really need that much fuel to travel around.

I guess the stasis pods do need to be constantly powered though... and some cogitator systems for monitoring purposes.

I remember in the Inquisition war seires Draco had a small ship that was capable of warp drive. Pretty sure it was said to be a little larger than a thunderhawk gun ship. I know that they placed themselves in times released statis casks to make a long warp trip to Terra.

Unfortunately with just about everything in WH40K it depends, and varies depending on who is currently writing.

I think Eldar have small ships capable of warp travel, I think the Rangers use them. Not sure, not an Eldar man myself.

Eldar avoid using the Warp like the plague. They use the webway if at all possible. Seems unlikely they would have small warp capable vessels.

But yes, it does seem to depend. Some things say that warp vessels need to be hundreds of metres long as a minimum, other stories have small warp capable vessels.

I was under the impression that Abnett's books are highly controversial (despite their popularity) as clashing with the setting as depicted everywhere else.

I personally would say "no." This is Age of Sail in space. You can't have a transoceanic rowboat.

I don't know how controversial they actually are, but there are various times they clash quite dramatically with the feel of the setting otherwise, and others where they flat out contradict stuff in other sources. The Gaunt's Ghost series is not 40k fiction. It is Sharpe written in a setting that is very like, but not quite the 40k setting. Lots of stuff in it that makes no sense background wise:

At one point it is a major plot element that they are sent the wrong type of lasgun charge packs. Firstly, the whole point of lasguns is their interchangeability. Any lasgun should be able to use any lasgun charge pack. Secondly: Why do they not just recharge the packs they had from the last battle they were sent on?

I would tend to agree on the transoceanic rowboat point.

The whole reason I bought up eisenhorn and ravenor was that they had small interplanetary ships that they used to dock with far larger warp-capable ones.

I would also point out to all the abnett-phobes that this is entirely in keeping with the existing background. I direct your attention to the aquila lander, the thunderhawk gunship and almost the entire range naval aircraft as examples of transatmospheric interplanetary ships without warp drives that dock with larger warp-capable ships for interstellar transport.

In short: small warp-capable ships are possible, but each would be a priceless piece of unique archeotech. Actually finding one should only be possible to the same degree as all the missing primarchs turning up alive, the Emperor getting better and wandering off or The entire Ork race giving up the bloodshed and becoming vegan turnip farmers.

I remember mention of warp cutters as a smallish ship capable of short warp jumps. I may be mistaken.

In short: small warp-capable ships are possible, but each would be a priceless piece of unique archeotech. Actually finding one should only be possible to the same degree as all the missing primarchs turning up alive, the Emperor getting better and wandering off or The entire Ork race giving up the bloodshed and becoming vegan turnip farmers.

And Khorne actually loving psykers.