Amtrak has unveiled plans to procure 40 additional coach cars for the Acela high-speed service in 2012 to increase seating capacity on all existing high-speed train sets, according to Railway Technology.

The plan is part of Amtrak's $2.22bn funding request submitted to Congress.

Under the procurement plan, each of the existing 20 Acela train sets will receive two additional coaches, increasing seating capacity by 130 per train.

This will lengthen the train set from a 1-6-1 configuration to 1-8-1 (power car - passenger cars - power car) and will also require modifications to high-speed rail maintenance facilities in Washington, New York and Boston, US.

The funding request for 2012 includes $1.285bn for capital investments to maintain and improve tracks, equipment and other infrastructure along the Northeast Corridor, $616m to support operation of 300 daily trains, and $271m for debt service.

Amtrak is also seeking $50m for design and preliminary engineering work on the Gateway Project to build two new tunnels into Manhattan and expand capacity at New York Pennsylvania Station.

If the procurement process begins next year, the first of the new Acela coaches would begin to enter service in 2014.