Pollock completed and launched her as a merchant vessel, the "Knox", for the London & Rochester Trading Co Ltd.. If you compare the photographs below with those of any of the other "Improved VICs" (eg VIC56) it is clear that the superstructures of "Knox" and her sister "Nervo" (VIC58) were designed with a much lower profile, presumably to aid navigation on the river Medway. The replacement of the standard steam engine with the TVO engine and other modifications including a reduction in freeboard to six inches allowed "Knox" to carry 250 tons of cargo, up from the original 167 tons.
For those not familiar with it, TVO, or Tractor Vapourising Oil, was a paraffin-based substitute for petrol introduced in the UK in the aftermath of WW2 and in use up until the early 1970s. During the manufacture of paraffin the aromatic hydrocarbons are removed from the distillate and as a result paraffin has an octane rating of zero, rendering it useless in an internal combustion engine. However, adding some of the aromatic hydrocarbons, which would otherwise have gone to waste, back in gives the resulting TVO an octane rating of around 65-70, making it usable as a fuel oil substitute. Alas, as a paraffin it still didn't vapourise very easily and the engine had to be started with petrol and heated up before switching to TVO.
Alan Jenner, who commanded "Knox" in the 60's has been writing to me with photographs and tales of life with his ship. I've put his stories together into a separate page, which you can access by clicking here.
The photographs below show "Knox" on the River Medway: on the left in 1968 when laden with 180 tons of bitumen barrels and on the right entering Allington Lock, also in 1968.