First Generation ISAH Drive - pre Union
ISAH Engines
Until the latest generation of ISAH drives (the Mark 51 Series of 5010) became standard, ISAH engines had to be used in dual configurations
(2, 4, 6, 8 etc) this was due to the utmost importance of Super symmetry and the co relation of Super exotic particle interactions (between their symmetric partners)
As the very first ISAH engines weren't as safe as the ones designed later , ISAH engines were mounted as "pods". The Pod design was (and is kept) as it frees interior space and the pods could be
easily serviced and replaced. The HALD explorers especially use this feature as they are equipped to replace entire pods while underway and far from space docks or ports.
However by the time of the new 51 series such engines have very little in common with the original ISAH Pods.They are utterly reliable (Within their expected service lifetime. Not a single incident is known where a Mark 51
needed so much as micro calibration or any sort of maintenance.
The new ISAH engines can be used in any configuration (1,2,3 etc) and can of course can be mounted inside ships. The benefit of mounting them inside is that the vital drive of a ship can be protected by additional armor.
More and more Union ship designs , both civilian and military are now trending towards the ducted or interior mounting option. (With the notable exception of HALDS Explorers)
The new Engines incorporate ISAH tech, Attikan tech and the design solutions of a thousand species and millions of engineers and scientists.
There is a debate over the official terminology and all possible terms have been used since the creation of ISAH engines:
ISAH PODS, ISAH Drive, ISAH Engines, ISAH Units.
The fleet officially calls them Quasi Space Slipstream Drive Units Type : ISAH. At least that is what they are called in the supply lines of logistics. Union fleet engineers call them ISAH Pods regardless of location and configuration and
the general public uses each possible term with no particular preference noticeably.
It is possible that the era of ISAH engines is slowly fading, as new drive technologies become available. Such as the Graviton Singularity Pusher with Hyper Space Tap (first used in the USS Tigershark) or the
Leyline Psi Drive (Leedei/Saresii/ DeNoir development) The whispered new SII Galaxy Drive based on Hyperspace drilling, allowing travel from Galaxy to Galaxy in mere days is probably still many decades if not centuries away.