Several more managed services are also on the cusp of being signed, he told Proactive's Andrew Scott.
At Tema, capacity is being increased to 3.5mln containers a year from one million currently and Westminster will earn a fee for each unit that passes through.
Westminster won a scanning contract for two Asian ports earlier this year, but Tema is different as it will be long-term recurring revenue Fowler said.
Final details are still being agreed but Westminster already has people on the ground helping to install the hi-tech scanners to be used at Tema.
Elsewhere, the aviation arm has seen record passengers at the West African airport where it provides security, while the training business is also going great guns as well said Fowler.