Heavier Volman workshop lathes were distinguished in the Company's advertising literature only by the rather unimaginative title of "18-Speed". In the smaller sizes there was a considerable overlap with the range of lighter lathes but, with weight increases of between 64% and 74% for a given bed length and approximately equal swing, the machines were very much more heavily constructed and with the option of even longer beds.  Although all followed a common design theme, six distinct models were produced distinguished, as in the "lighter" range, by the use of completely different main castings (bed, headstock, carriage and tailstock) and with each version offered in two relatively close centre heights the smaller of which was identical to that used on the larger of the model-pair below. Counting all the options possible by varying the bed length and centre height a total of 54 different lathes were offered.
The smallest example, Model JOKN/1, had a centre height of 71/8" and a capacity between centres of 40"; three other bed lengths were offered giving 59", 79" and 98" between centres with weights spanning 2050 to 2490 lbs. A typical  mid-range lathe in the series would have been the l JZTN/6 with a centre height of 10 1/4 inches and a choice of 40", 59", 79", 98", 130" or 138" between-centres and weights that varied from 3620 to 4850 lbs. The largest machine of all, the 153/4" (centre height) by 196" between-centres JMN/8 weighed, at 18,750 lbs, nearly eight and a half tons.
Although the configuration of the various machines was very similar Volman were not tempted to economise by sharing components; each model had its own speed range so that it was best suited to the type of work it would encounter; the headstock spindles were different with, until the two largest machines, increasingly large bores (even then the larger in a series had a bigger Morse centre); the leadscrews were, likewise, increased in diameter (if only by an insignificant 1/8" across the two largest models) and the screwcutting gearboxes re-engineered for heavier work with 3 different thread ranges shared amongst the six models..

Carriage as used on the L-22, L-25 and larger lathes. The star-shaped knob enabled the operator to get a better grip when operating the more powerful multi-plate power-feeds clutch used on these models. The extended saddle wings acted both as covers to protect the leadscrew and handy tool trays.

Apron as used on the N-16, L-18, N-18 and L-20 lathes. Larger lathes had the modified and strengthened unit shown below.

18-speed headstock as fitted to the Type N, L and T lathes. The two multi-plate forward and reverse clutches can be seen in the rear left-hand corner of the box.

12-speed headstock as fitted exclusively to the N-18 and L-20 T lathes. The two multi-plate forward and reverse clutches can be seen in the top left-hand corner of the box.