Metra, a commuter railroad owned by Regional Transportation Authority in the US, has issued a request for proposals (RFP) to purchase new or remanufactured locomotives as part of an initiative to replace its aging fleet of engines.

The new RFP aims to order at least 12 new or 15 remanufactured locomotives, with options for up to 30 additional new or 27 additional remanufactured locomotives to increase its fleet to a total of 42 units.

"The proposal calls for both new and remanufactured engines, as Metra intends to assess the costs and benefits of both options."

The introduction of new locomotives is intended to enable the company to replace its old diesel locomotives with modern engines, which will in turn also improve air quality.

Metra has allocated a total budget of $125m for the acquisition of locomotives in the next five years.

The proposal calls for both new and remanufactured engines, as Metra intends to assess the costs and benefits of both options.

The company also plans to evaluate other possible financing alternatives, including leasing, to maximise the utilisation of available capital.

Metra previously announced its intention to buy 367 railcars and 52 locomotives over a ten-year period as part of its 2014 modernisation plan, subject to the successful procurement of $1.3bn funding, which will mostly be procured through a new state bond programme.

The funding is yet to be received; however, the company intends to continue the modernisation programme with its existing funding and capital resources in the meantime.

Metra plans to award the locomotive contract later this year and the first locomotive is expected for delivery in 2020.

The company also issued an RFP to acquire at least 25 new railcars in April last year.

It is currently evaluating the responses and plans to award the contract later this year.