AR Watson International is a mechanical engineering construction business, supplying services to the petroleum, petrochemical and gas industries. AR Watson has developed a reputation as a capable contractor able to handle large projects, providing innovative and cost-effective solutions to engineering problems worldwide.
AR Watson’s primary focus began in developing a unique method for lifting or relocating above ground storage tanks for tank maintenance. Lifting a tank allows the best access for bottom / foundation maintenance or replacement, however there are other reasons that an above ground storage tank may need to be lifted and eventually moved. Relocation is a valuable tool for tank owners and operators, allowing cost-effective time saving solutions to consolidate assets or facility upgrading and expansion.
The tank lifting technology was created in New Zealand in 1980. The use of Watson Air Lift® technology (airbag system) is widely accepted as a better option than cutting the tank down (as stated in API 653 also EEUMA 159). The technology utilises air bags placed beneath the tank shell to lift the tank. Each air bag will lift 70t, and lifts tank approximately 150mm (6in) per lift. This is repeated to lift the tank to any height required.
The company has worked on 1,500 bulk storage tanks of various sizes up to 95m (300ft) in diameter, some weighing in at a massive 1,800t. Safety is the number one priority within the oil and gas industry, and to date the company safety record exceeds that of any other company worldwide.
AR Watson’s diverse experience within the industry includes pipelines, refineries, terminals, airports, air force bases, and work with all of the major oil companies worldwide such as BP, Caltex and Mobil.
AR Watson takes extensive engineering calculations on the tank to take into account not only the stress to the tank but also local conditions, such as wind and seismic activity. Insurance is at the highest standard with our policy, covering worldwide coverage and workers combinations.
Tanks lifted 2012
One of the many contracts completed in 2012 included lifting and relocating a tank of 107ft in diameter at Lake Charles, Louisiana, US, in January. The tank had its floor removed and cables were added to support the columns. It was then lifted and relocated 25ft away by railway tracks and bodies. The tank was lifted and supported on I-beams, so that a new concrete ring wall and tank floor could be contracted under the lifted tank.
In February at Nellis Air Force Base in Las Vegas, Nevada, US, two tanks were lifted for floor replacement and CP repairs with both tanks 30ft in diameter.
In Chile a 95ft diameter tank was lifted to remove contaminated soil, this tank was in operation for only four days when a leak was detected.
In March at Tampa, Florida, US, a 60ft diameter tank was lifted for tank bottom repairs and liner installment into the foundation. This work was done whilst working underneath the lifted tank.
Another job began the same time so another team was sent to Bakersfield, California to work on a 95ft diameter tank with settlement issues of 18in on one side. The plan involved attaching cables around the top annular to support the floating roof and also the tank floor, lifting the tank to correct the settlement issues and re-level it. It was then lifted further to a height of 6ft, so repair was carried out to the concrete ring wall and foundation.
Other contracts completed in March and June of 2012 in the US include the lift of a tank for McGhee Tyson air force base, Tennessee, for foundation repairs; assisting a contract company Cape to lift a floating roof in Texas; and relocation of two 40ft diameter tanks in Wainwright, Alaska, which were transported 80ft so that new foundations could be built, then relocated back after the new foundations were finished.
Currently AR Watson has a contract with BP to move five tanks in the next three years in Deadhorse, Alaska. Work has begun on 45ft diameter tank relocation, so foundations can be repaired. In both Wainwright and Deadhorse, all tanks have been relocated by using I-beams and load skates. AR Watson also has a 96ft diameter tank in Mozambique that is currently being worked on for BP. This tank has had a double bottom base in which both bottoms have failed, so both floors have been cut away from the tank shell. The tank was lifted to 6ft to give local contraction company G&B room to remove the old floors and repair the foundations, and rebuild a new tank bottom under the lifted tank.
Lifting the tank transforms it from a confined space into an open area where access is free, preventing time loss on repairs and a cost-efficient method. The company is also currently building contracts in Australia with a company called Universal Cranes, to lift three tanks that are going to be relocated to barge and tug boats then shipped from Tasmania up along the east coast of Australia to Newcastle, a sea journey over 1,000km in open water. All this work and it is only August 2012, so it has certainly been a busy year for AR Watson.