- Running number: Uc2471 (Originally Uc1315)
- Designed by: New Zealand Railways
- Built at: NZR Petone workshops
- Date built: 1954
- Builders diagram: Uc15
- Date entered service: 1954
- Date withdrawn: Around 1998
- Returned to heritage operation: November 2004
- Current condition: Certified for Network operation.
Uc2471 nearly finished.
- Weight in working order: 17 tonnes (Tare), 35 tonnes (Gross)
- Overall length: 40 feet. (12.2 metres)
- Bogies: Davis & Lloyd, with package roller bearing wheel sets.
This vehicle is one of a batch of 93 similar vehicles built between 1947 and 1955 for use by various companies including Shell, Caltex, British Petroleum, Associated Motorists, Tasman Pulp & Paper Company, and New Zealand Railways. Sixty two of the wagons were designed to carry 6300 gallons of motor spirit (petrol) and the remaining thirty one, those for Tasman and NZR, 6000 gallons of fuel oil.
Uc2471 was one of the petrol tankers, built in 1954 as Uc1315 for British Petroleum. Little is known of the wagon's history in everyday service. Like most wagons, it probably travelled many hundreds of thousands of miles all over the system and suffered its share of accidents, derailments and shunting damage. The original bogies were the Davis & Lloyd type fitted with plain bearing axleboxes. At some time in its history the bogies were converted by NZR to take package roller bearing wheel sets. The underframe, complete with bogies, was purchased from Tranz Rail in 2001 and the tank body donated by the BP oil company.
Soon after delivery to Steam Incorporated a survey of the wagon was carried out to determine what work was required to enable it to be certified by Tranz Rail for main line operation. It was intended that the vehicle be converted to carry water for use as a steam locomotive support vehicle, when required, in passenger excursion trains. As far as was possible, the wagon should retain the appearance it had when in every-day service as a petrol tanker.
To meet the intended use the following modifications to the original design were carried out during the restoration:
- The tank was fitted with additional internal baffles to allow the vehicle to run safely when part full.
- Automatic fill limiters were fitted to prevent the tank from being over filled. Because of the higher density of water compared to petrol, the maximum cargo was limited to 4000 gallons. Major re-design of the bogie springing would be required to allow 6000 gallons of water to be carried and this may be done in the future.
- An automatic slack adjuster was fitted to the brake gear to eliminate the need for regular brake adjustments
- The brake cylinder was fitted with a type WP10 triple valve, with a P10 exhaust choke so that its braking characteristics were more closely matched to the passenger vehicles with which it would normally run.
- A feed pipe was installed so that a suitably fitted steam locomotive tender could be continuously fed from the tank, thus doubling the range of running between water stops.
The internal filler pipes before fitting to the tank. These are designed to minimise aeration of the water when filling the tank.
The first steps in restoring the vehicle were to remove the bogies, the drawgear, the brake cylinder, brake piping and other components below the underframe, the straps that hold the tank down to the underframe, and the rotten wood platforms and handrails. The underframe was then put up on stands and the underframe and tank sand blasted all over and painted with primer.
The bogies were completely overhauled, the underframe repaired and straightened, the drawgear overhauled, new brake piping and water feed pipes fitted, and the original tank emptying pipe modified to become the tank filling pipe. Inside the tank additional baffles were fitted, so that the vehicle can safely run part full, and an internal inverted syphon fitted to avoid aeration of the water when filling.
When these vehicles were in every-day service they ran either completely full or completely empty, so movement of the contents was not a problem. As a locomotive water tanker, they are required to run with the water level slowly lowering, so means must be provided to control the movement of up to 18 tons of water. Hence the extra baffles required. New timber platforms were made and the handrails repaired.
The vehicle is finished in the traditional gloss black paint, with the hand rails, ladders, footsteps, and hand brake picked out in white or yellow as required by present day regulations.
Because of its gross weight, the use of this vehicle tends to be restricted to empty train movements when it is desirable, for timetable reasons, to avoid water stops.