In The Algebraist, a key element of the plot revolves around portals, with the Algebraist itself being a list of co-ordinates to Dweller portals. Early in the story we hear about the destruction of a portal, during which we learn of the following limitation:
Portals were only ever positioned at Lagrange points or other orbits distant from large heavenly bodies because they needed a section of space-time that was relatively flat. Too great a gradient - too near the gravity well of a planet or other large object - and they stopped working. Increase the S-T curve only a little more and they imploded and disappeared altogether, usually violently.
Later in the book Fassin Taak discovers the transform required to determine the Dweller portal co-ordinates from the list and all seems to make sense, except perhaps for this:
The only way to get an arteria portal from one place to another was to put it in a spaceship and physically take it, slower than light, from one place to another, leaving the other end – usually – anchored where you'd started out.
How did the Dwellers actually move a portal from its initial point to its final destination, without destroying it at either end? Is this a significant plot hole?