• Running number:Uc185(Originally Uc804)
  • Designed by:New Zealand Railways
  • Built at:NZR Petone workshops
  • Date built:1926
  • Builders diagram:Uc-3
  • Date entered service:1926
  • Date withdrawn:Around 1988
  • Returned to heritage operation:October 1988
  • Current condition:Certification for Network operation has lapsed.


Uc185 at Paekakariki in Dec 1996. Photo John Bovis

Image: Uc185 at Paekakariki in Dec 1996. Photo John Bovis

Wagon details

  • Tare:17 ton 6cwt
  • Overall length:30 feet. (9.14 metres)
  • Bogies: 25830 Davis & Lloyd.


During the eighties an essential piece of rolling stock although rather curiously rarely seen in that light, was Steam Incorporated’s vintage support tank wagon for refueling Ka 945. Irrespective of whether it was trailing our famed 4-8-4, or patiently waiting at a future servicing location to refuel #945.This first operational locomotive service wagon during the operation of 945 become an indispensable component in the successful running of the majority of our Ka 945 powered excursions.

The history of Uc 804 goes right back to the early days of bogie tank wagons on the New

Zealand Government Railways. Built during 1928 by the Petone Railway Workshops, our feature tank wagon was one of 16 (road numbers 803 to 810 and originally assigned to the

North Island: and 821 - 828 for the South Island) constructed that year to a common design that was classified as type Uc-3. Unlike the contemporary single dome Uc-1's and Uc-2's, the 4910 gallon (22,300 litre)Uc-3’s featured a distinctive riveted double compartment twin-dome tank mounted on a thirty foot long (blueprint) number 3922, type U-3 flat deck bogie wagon. The wagons were originally fitted with type 3181 "archbar" bogies, although over the years these were replaced with both type 25340 "fabricated" and type 25830 "Davies & Lloyd" bogies.

Built for and originally owned by the Vacuum Oil Company Pty Ltd., the 16 Uc-3's were painted in a striking "billboard" lettering scheme of glossy black and silver lettering, proudly advertising the Vacuum Oil Companies "PLUME" brand of motor spirits (as petrol was known in those days), on both the sides and ends of the tank body. Over the years the

Vacuum Oil Company was succeeded by the Mobil Oil Company, and in the process Uc-804

and the 15 relatives took on a more utilitarian appearance of flat black, and just the standard NZR reporting lettering and statutory warning signs as appropriate for the flammable cargoes carried by these groups of tank wagons.

Uc-3 drawing

Line drawing of a type Uc-3 wagon in essentially as built condition with type 3181 bogies and without the tubular steel hand rail cage mounted around domes on top of the tank. Reproduced with permission from the New Zealand Model Railway Guild Inc.

Initially used to deliver refined fuels to the inland fuel depots located all over the country this use was phased out with changing methods of fuel distribution using tank truck delivery from the port terminals direct to the end customers allowing the closure of the small intermediate depots.  The remaining rail fuels traffic was taken over by more modern and larger tank cars. However most of the Mobil Uc-3s survived into the eighties by being reassigned for a new use.  This was transferring bulk lubricating oil from a lube blend plant at Seaview (Gracefield) to plants at Auckland, Hamilton, Woolston and Dunedin. From these locations the oil was either locally repacked or delivered by dedicated bulk tanker to the service station and garage workshops or to commercial customers.  The two compartment Uc-3s were ideal for this traffic. 

Demonstrating the remarkably long lifetime of tank wagons, the majority of the Mobil Uc-3 class were still on the books at the start of the 1980's. By the mid-l980’s, Uc-804 (renumbered by now in the TMS registry as Uc-185) was pretty much surplus to requirements. Concurrently with the return of Ka 945 to active service, it was recognised that storing fuel oil at Paekakariki, as well as moving the fuel oil around the country to support the locomotive would need to be addressed in the near future.  As fate would have it, the solution to the problem was tank wagon Uc 804/185.

Through the good office of John Bovis of Mobil Oil N.Z. Ltd, the tank wagon was generously donated to Steam Incorporated during the Winter of 1988. 


On arriving at Paekakariki, the Uc was given a number of repairs including replacing corroded areas of the frame and deck plates, while the brake equipment and bogies were overhauled in preparation for the wagon being ready to once more earn its keep hauling fuel by rail. Internally, new anti-surge baffles were fitted to the tank compartment. Finally, with the mechanical details duly taken care of the wagon was repainted in basic black, safety handrails and grabs lined out in white, and lettering for both Mobil Oil and Steam Incorporated affixed to the sides of the tank body.

In its new service Uc 804 was first used by the Society to haul fuel oil to Palmerston North for the "River City Railranger" steam excursions to Wanganui over the weekend of 22/23 October 1988. Since then. Our fuel oil service wagon has been used on a number of Society train trips, and become a familiar sight trailing Ka 945's tender.

Crunchie Train Forest Lakes with  Uc 804/185

Uc185 in use on the North Island Crunchie Train May 1993

As a postscript to this brief history of Uc 804, it is interesting to note that Steam Incorporated later took delivery of a second Mobil Oil Company type Uc-3 tank wagon, Uc 826 (TMS #317), for primarily static storage purposes at Paekakariki.  In 2015 Uc 826 moved to a new home at the Silver Stream Railway.

The Mobil Uc-3 tank wagons are survivors!  Of the 26 built back in 1928 eleven still exist today and besides 804 & 826 can also be found with Mainline Steam, Pahiatua Railcar Society, Feilding & Districts Steam Rail Society, SteamRail Wanganui, Waitara Railway Preservation Society and Dunedin Railways.

Uc 185 on an excursion

Uc185 tucked in behind Ka945 nearing Waiouru. Photo Ray Mathewson

For the 9mm NZR modeller a 3D printed (in China) ready to run model is now being offered by the 9 Mil Store for about 400NZD. See the NZ Model Railway Guild for details.

These notes are based on a feature written by Reid McNaught for a 1991 issue of our “Steamline” newsletter.

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