Two types of end stanchion tooled: NER wooden or LNER metal 'T' bar type from 1925 onwards. After 1926, the bottom sections of any remaining wooden stanchions were removed.
Side chains were fitted to NER Northern Division examples until 1916 and have been catered for.
Five types of axle-box: 3A Grease, Iron-Oil S1 (9” x 4.25”), Iron-Oil S2 (9.5” x 4.25”), No.3 (10” x 5”) & S4 single (10” x 5”), all of which have been tooled.
Differing brake arrangements tooled: Morton single shoe per wheel pattern brakes and Morton Cam pattern (diagonally opposed).
Handbrakes can be end, or side fitted, with two types of side handbrake arrangement catered for.
Body ends will feature the removed central section of bottom plank for Northern and Central Division incline hauled hoppers, as well as the Southern Division solid end.

Having been influenced by witnessing coal haulage operations in the United States, where tradition did not hinder working practices and facilities, the Board of the NER decided to improve the ratio between capacity and tare weight of their waggons by building larger capacity rolling stock. Ideally, this would have meant moving to steel bodied bogie hopper wagons, with a 40 to 60 ton capacity, but the restrictions placed upon wagon stock by the cramped rail layouts of many of the collieries, the height of the loading screens and the investment required in modernising the shipping staithes and coal depots under its control meant that the NER needed to standardise on wooden bodied 20/23 ton 4-wheel hopper types.

Still mindful that colliery owners would resist investing in new facilities, the first of the new enlarged vehicles to be ordered was the Diagram P6 hopper in April 1902, with a capacity of 15 tons, a wheelbase of 10' 6”, a length of 20' 0” and 8' 3” in height. 1,800 vehicles of this type were produced with both side and end brakes, but they were essentially an interim design, created to make the new approach palatable to the colliery owners. Within a month, in May 1902, a 20 ton prototype version was created, fitted with higher sides at 9' 10” and better suited to incline operations.

The Diagram P7 hopper was built in huge quantities, the majority by Shildon; the original order for 550 vehicles increasing to over 12,000 by Grouping in 1923 and again, both side and end braked versions were built, as well as with modifications to the end panels that made for safer operation on curved inclines in the Central and Northern Divisions.

A further development by the NER saw the fitting of anti-friction rollers to the type, resulting in an increase in capacity to 23 tons, creating the Diagram P8 hopper. The friction rollers decreased the starting resistance of a train and from 1906 around 6,400 wagons were fitted in this manner, before having the friction gear removed around the time of Grouping, when they reverted to the classification of diagram P7 and a reduction in capacity to 20 tons.

As with the haulage of commercial coal, the transportation of locomotive coal was transformed at the beginning of the 20th century by the development of the Diagram Q3 loco coal waggon, based on the P7 type. The Q3 was introduced in 1902 and featured a flat floor and a single set of doors on each side for the unloading of the coal, although the NER required them to be convertible for use with ordinary coal trade traffic and so hinged sloping floor panels were fitted, along with two latitudinal bracing struts to maintain the wooden body's integrity. Like the P8 hoppers, the Q3 hoppers were originally built with friction rollers and a 23 ton capacity, but by Grouping the friction gear had been removed and the capacity reduced to 20 tons.