Ownership DBP Transmission (DBP) is the trading name of the DBNGP group of entities, ultimately owned by the consortium comprising DUET (Diversified Utilities and Energy Trusts) - 60%; Alcoa - 20%; and BBI (Babcock and Brown Infrastructure) - 20%. DBP is responsible to the owners for the operation, maintenance and expansion of the Dampier to Bunbury Natural Gas Pipeline (DBNGP). Australias largest gas transmission pipeline. The Pipeline (DBNGP) The Dampier to Bunbury Natural Gas Pipeline (DBNGP) extends almost 1600km from the Pilbara region to the South-West of Western Australia. It is one of the longest and largest capacity natural gas pipelines in Australia supplying natural gas to industrial, commercial and residential customers in Perth and major regional centres along the pipeline route.