| LSWR H16 class | |
| Powertype: | Steam |
| Builder: | LSWR Eastleigh Works |
| Builddate: | November 1921 – February 1922 |
| Totalproduction: | 5 |
| Whytetype: | 4-6-2T |
| Uicclass: | 2C1 h2tG |
| Leadingdiameter: | 3feet |
| Driverdiameter: | 5feet |
| Trailingdiameter: | 3feet |
| Length: | 46feet |
| Width: | 9feet |
| Height: | 13feet |
| Axleload: | 19.8LT |
| Locoweight: | 96.4LT |
| Fueltype: | Coal |
| Fuelcap: | 3.5LT |
| Watercap: | 2000impgal |
| Firearea: | 27square feet |
| Tubesandflues: | 1267square feet |
| Superheatertype: | Eastleigh (later Maunsell) |
| Superheaterarea: | 231square feet |
| Fireboxarea: | 139square feet |
| Boilerpressure: | 1802NaN2 |
| Cylindercount: | Two, outside |
| Cylindersize: | 21x |
| Tractiveeffort: | 282001NaN1 |
| Operatorclass: | LSWR / SR: H16 |
| Nicknames: | Green Tanks |
| Withdrawndate: | 1962 |
| Disposition: | All scrapped |
The LSWR H16 class were five 4-6-2T tank locomotives designed by Robert Urie for the London and South Western Railway (LSWR) in 1921–1922. They were the last new design for the LSWR and their only Pacific-type design.
As part of the project to construct a marshalling yard at Feltham in West London, Urie produced two locomotive designs, the G16 "Black Tanks" to shunt the new yard, and the H16 "Green Tanks" to work transfer freights to the London area yards of the other railway companies.
When originally built they were numbered 516–520.
On passing to the Southern Railway, they had their LSWR numbers prefixed with an 'E'. The locomotives lost the prefix between 1931 and 1932. Under the new locomotive classification system for constituent companies of the SR, they were classified as G6/7/ for Goods, Grade (hauling power), Power and Range (route availability). The Southern Railway painted the H16 class in passenger green paint, rather than goods engine black.
All five engines were passed to British Railways, who renumbered them 30516–30520. All were withdrawn in 1962, and scrapped.