Project Description

The Marshalltown Generating Station is a 650 MW 2 x 1 combined cycle natural gas-fueled power plant owned by Interstate Power & Light (Alliant Energy). This plant consists of two Siemens 501F gas turbines (SGT6-5000F, 230 MW each), two Nooter Eriksen HRSG’s and one Siemens steam turbine (SST6-5000). Construction began in the fourth quarter of 2014 and the plant went online the fourth quarter of 2016. This facility includes a full building enclosure of the STG, CTG’s and HRSG’s to allow the owner better year-round equipment maintenance and winter cycling abilities.

Boldt’s scope of work included:

• Building layout

• Forming, pouring and finishing of all concrete

• Erection of all structural steel

• Rigging, unloading and storage of materials and plant equipment

• Rigging engineering

• Installation, alignment and grouting of centerline equipment

• Erection and weld out of HRSG’s

• High pressure HRSG interconnection piping

• Installation, alignment and grouting of balance of plant equipment

• Supply of all cranes over 100 ton