Underspace - I'm a little confused

[Vertigo]

I'm two thirds through my first Asher book and loving it so far however I am a little confused by something.

Spacecraft with underspace drives take months to get somewhere yet runcibles using the same underspace are instantaneous. As they both appear to use the same technology why the big difference in time? I did read the bit describing underspace:

"There's no time there, no distance, nothing. From there all runcibles are in the same place and at the same time. Shove a human in and he doesn't cease to exist because there is no time for him to do so. Pull him out. Easy."

However I don't quite see why the "no time, no distance" bit doesn't also apply to spacecraft.

 

[Null_Zone]

I believe it is to do with energy requirements.

Runcibles draw on the power of suns, geothermal powerstations and the like to move a small amount of mass -one person, quickly. Whilst a ship is considerable more mass so to do it as quickly would require more power than it could generate.

 

[Vertigo]

Ok I can sort of get that but my impression was that the energy requirement was to get you in and out of underspace, but once there everything should have been instantaneous.

 

[Neal Asher]

Null Zone, that about nails it. However, being an honest sort of chap I have to note that my ships are governed by one of the immutable laws of SF: the speed of plot.

 

[Wraitholme]

Pratchett calls it narrativium, the particle that governs the odd laws of the universe responsible for the various coincidences, plot holes and strangely common events required for an interesting story to manifest.

A common signature of narrativium in our universe is of course Murphy's Law.

Potential psuedo-explanations for the varying actions of underspace, created simply because it's fun to think about them
(Yes I am the kind of person that enjoys picking apart Star Trek technobabble. Why do you ask? )

1) Drawing from Null Zone's idea... based on the amount of energy available, the underspace 'drive' device has a limited range in underspace in which it can 'place' the object being transmitted. This assumes that underspace and realspace have corresponding positions between the two realities.
So the Runcible, with a huge power supply, has the 'reach' to overlap with the other runcibles... it can place the relatively small object far enough 'away' in underspace that the other runcible can then pick it up.
The ship, on the other hand, has a small 'sphere' that it can drop itself in, and needs to travel for a realtime period to reach a sphere around the desired arrival point.

2) Discarding the above, one could simply posit that the act of carrying the drive itself through underspace changes the fundamental rules of travel within it. The runcibles are static realspace systems that reach into underspace, while the ship drive must necessarily travel with the ship.
This does, however, leave us with a slight conflict over the ship runcible in Prador Moon, which required a travel time (at least, in the way that I understood it).
I would be interested also to know how the USER interferes with runcible transmission.

 

[Neal Asher]

Ah, a USER is a singularity regularly dipped in and out of underspace to cause waves, disruption. All that stuff about the drive being in the ship and the runcible being a static device is implicit. I think the analogy I made in an earlier book was between a tunnel under the sea, with a powered railway, and a submarine.