The 1976 Intapak (for Intermittent Packer) was probably aimed squarely at the Colectomatic, a design popularized by Heil which was sold in England by way of Jack Allen Motor Bodies, Birmingham. Simply put, the hopper was in fact a hinged trough which was raised as the packer blade simultaneously opened rearward. Once fully raised, the packer blade reversed, scraping the refuse from the trough and into the body. In the SD incarnation, the packer panel was operated by externally mounted cylinders, driving the blade pivot shaft through bell cranks.
This was a short-lived model for SD, and a design which was becoming obsolete by the mid 1970's. Generally, the 'Colectomatic' principle was a sound concept, but suffered from a major shortcoming; no refuse could be loaded during the packing cycle. The 'slide-sweep' intermittent loading rear packers (which were starting to dominate America) could be reloaded before the cycle was half complete. And of course there was Shelvoke's own Revopak, which chewed refuse without interruption and would out-pack its stable mate.
Heil's 'Colectomatic' hinged-hopper packing method was widely copied in the U.S. and Europe over several decades, but by 1976 was on the way out, and would virtually disappear during the 1980's. Thus, the Intapak perhaps may have suffered from a case of bad timing as much as any other factor.
'P' TYPE REVOPAK
An all-new truck series debuted in 1978, the 'P' Series with a steel cab now made 'in- house' by Shelvoke, which was developed at a relatively low cost. Specialist builders such as SD could not afford excessive design and production costs because of the small number of vehicles produced for sale. The 'P' cab consisted of a simple framework which was then finished with various sized steel sheets. The group that designed this futuristic-looking new chassis was headed by none other than Tom Tillson, who had developed the 'T' Series back in 1959!
As one would expect, the modern Revopak adapted to virtually any container, including the ancient round Palladin bins shown in these pictures.
Successor to the compact 'N', 'TN' and 'NN' range was naturally the 'PN' Revopak. This 1982 ex-Isles of Scilly example remains in preservation. It is the pride and joy of Steve Jones of Sandown, Isle of Wight, who saved the magnificent machine from oblivion. It has been featured on the TV show "Salvage Squad", and has appeared at commercial vehicle shows. It is, of course, fully operational, as can be seen in the video below:
'P' TYPE MAXIPAK
Though obviously sharing many components with 'P" Revopak, 1978's new Maxipak body was in fact a very conventional slide-sweep type intermittent rear loader. Concerns about fuel consumption may have been driving the trend away from continuous loaders at this time, thus allowing the slide-sweep style to gain a stronger foothold in England (as well as in continental Europe). Looming or anticipated safety regulations may have also been a factor. Shelvoke's long-time rival Dennis had also introduced their own slide-sweep rear loader, The Eagle, during this period.
