Most 0-6-0 tender type locomotives throughout the UK were primarily used on medium weight goods duties. This included the J36.
The scope of these duties included transfer work from yard to yard of general goods traffic. More importantly they would handle yard to station trip work, including 'pick up' goods which brought loaded wagons for unloading and empty wagons to be loaded from the marshalling yard to the local station goods yard, and then returning to the marshalling yard with those wagons already unloaded / loaded.
Pick up goods would travel along a line of route calling at different goods yards on the way, attaching and detaching, so from station to station the composition of the train would change.
While at the goods yard the 0-6-0 would be used for shunting the wagons into the correct places for loading / unloading, and making up the train to proceed to the next station.
Where there were private sidings belonging to factories and collieries the locomotive would exchange wagons which would be moved internally by the firm's own locomotives. Special exchange sidings would usually be provided where inwards wagons would be detached, and outward wagons attached. It was common to find a notice board within the exchange sidings stating main line locomorives should not pass it.
On return to the marshalling yard the 0-6-0 would leave its train in a 'Reception' siding where a shunting engine would then sort out the wagons for the next service. The 0-6-0 would either go on shed for coal and water, or toddle round to the departure sidings where the shunter will have set up another train for other sidings in the area.
In terms of what would be in the train, coal was undoubtedly the most common load, most stations had at least one coal merchant who received a dozen ot more wagons per day. Many trains consisted only of coal wagons especially in coal mining areas, where collieries needed empty wagons every day, filled them and sent them out daily. Over half the railway's fleet of wagons were exclusively for coal traffic. 700,000+ vehicles in the 1940s.
Hopper wagons were usually limited to industrial users, coal for merchants invariably arrived in small box type mineral wagons, initially 6, 7, or 8 plank high 13 ton mineral wagons (expecially before 1948) but latterly in steel bodied 16 ton mineral wagons.
Perishable and vulnerable traffic, ( e.g. cases of tobacco, washing machines, cases of bottles and barrels of various alcoholic drink etc.) would be in covered vans sealed with devices checked by the railway police, these had to go inside the goods shed for security. Less vulnerable goods would be carried in open wagons but then usually covered by a tarpaulin sheet to keep the load dry. If there was room this went into the goods shed too.
Bricks sand and building materials were conveyed in open wagons. Builder's merchants often had a part of a goods yard where they could receive and store their materials.
Timber would be in open wagons or bolster wagons, and placed near a crane to make unloading easier.
Cattle in cattle vans, would be placed alongside a cattle dock so the animals could walk off the wagon but be kept penned and secure until collected by the butcher or farmer.
The 0-6-0 was a 'maid of all work' and could be called upon to work local passenger and parcels trains too. However it was hauling the goods that was their 'bread and butter'.