There are at least 3 types of Utility Vans seen in the Railway Series and television series.
They are also simply known as vans or trucks in the UK narration or cars in the US narration.
General Utility Vans
These type of utility vans are primarily used for transporting letters and parcels throughout the railway.
The Railway Series
These vans are based on general utility vans (GUV), however their specific basis is unknown.
These vans are painted light brown.
SE&CR Diagram 960 PMV (4 wheels)
These vans are a type of rolling stock used for transporting goods and merchandise throughout various railways. They have 4 four wheels.
These vans were slowly phased out by the fifth season and replaced with bogie variants, as they ran easier on tighter turns.
Thomas & Friends
They have often been used for the Flying Kipper with other types of vans and have been involved in many accidents while part of the train. Such as derailing into a stationary goods train and being completely submerged underwater after travelling on a line eroded by high tides.
Sentient vans fall into the category of Troublesome Trucks.
The utility vans are based on the South Eastern & Chatham Railway Diagram 960 Parcels and Miscellaneous Vans (PMV), introduced in 1919.
This van was designated the standard for the Southern Railway, and remained in production, updated as the Diagram 3103, until 1951, remaining in regular service until 1986, with a few surviving on departmental duties into the 1990s. These vans were used primarily for the transportation of letters and parcels.
These vans were originally painted dark brown with light brown vents. They were repainted a faded black in Season 3.
SE&CR Diagram 960 PMV (bogie wheels)
These vans are a common type of rolling stock used for transporting goods and merchandise throughout various railways.
These vans replaced the 4 variants, as their bogies allowed them to run easier on tighter turns.
Thomas & Friends
Henry once used one of these vans to transport letters and parcels from the Mainland to Percy's Post Train. .
Though faceless one of these vans once pushed Thomas down Gordon's hill, thus making them troublesome trucks.
The utility vans are based on the South Eastern & Chatham Railway Diagram 960 Parcels and Miscellaneous Vans (PMV) with added bogies. The mail vans share the same basis.
These vans are painted dark brown, cream, dark grey, and blue.
There have also been vans with special liveries depicted with logos for various businesses and companies.