Following the destruction of his initial batch of loyal Daleks created on the planet Necros, Davros drew up blueprints for an improved casing. This Mark Four Travel Machine became the foundation for the drones within Davros&##039; own Dalek Empire and achieved a great number of victories over the Loyalist Dalek forces (those loyal to the Dalek Prime). In most respects, this casing was superior to the Mark Three casing. At the conclusion of the civil war, the Dalek Prime briefly considered implementing the Mark Four as the standard casing for the Dalek Empire. Ultimately this design was rejected as a product of Davros' insanity, but elements of its design were incorporated into the Mark Three casing.
The Mark Four took the Mark Three design as a starting point and improved on it. The majority of the casing was similar to the Mark Three, and the untrained eye could often confuse the two. The luminosity dischargers were of a more efficient design, and the "eyestalk" allowed for superior targeting and a number of enhanced vision modes that were unavailable to previous designs. The standard "sucker" arm attachment was of a new, slot-lock design but it retained the extendible data-probe. As with all casings, alternative arm configurations could be installed from outlets in Dalek ships and buildings. The energy weapon usually seen was a different design to those of previous casings, and the output was reduced slightly to limit the drain on the casing's reactor. This made the weapon somewhat less effective than that of the Mark Three casing.
The majority of the differences between the external casings were aesthetic ones that had no real bearing on the casing's function as a mobile habitation unit and war machine. As with previous designs, there were fifty-two (52) sensor globes located around the skirt section of the casing. The formula of the bonded-polycarbide used in the construction of the Mark Four was improved over the previous iterations, the lattice providing better protection to the occupant. The power generator of the Mark Four was more powerful and the motive unit allowed for extended periods of levitation up to sixty centimetres in height. Advanced gyroscopes meant that the Mark Four allowed for quicker acceleration and sharper cornering than the previous deisgn.
A scout version of this casing was sighted on many battlefields. This consisted of a larger, wider base unit (similar to the attachment seen on Mark Two Travel Machines). This variation was far more manoeuvrable and faster than any other standard casing. Additionally, the sensors installed within the casing were more sophisticated than in any equivelant casing – from the data gathered rapidly by Scouts, a more thorough view of a planned assault area could be derived than by using orbital scanners and ranger-scopes only. Two downsides to this casing were its limited fire-power capability (sufficient for the extermination of a good number of life forms, but not so useful against the Loyalist Dalek faction) and the lighter polycarbide shell which provided less protection to the occupant.
Remembrance of the Daleks, Emperor of the Daleks, Terror Firma. Scout model – Remembrance of the Daleks (Novelisation).
