The Secret Pipesmen are a not-terribly-secret society in the town of Nsburg. According to Alex in Episode 1, they mostly "get loaded on weekends and take care of the highways." They have recruiting posters up in the Town Hall (both of them). Ralph from the Geological Society seems to be the Pipesmen's spokesperson, or at least its most polite member.
The Secret Pipesmen have been attempting to build a light rail project in Therpston County for the past 18 years, although nobody knows about it because it's a secret. Each election year the society coordinates a protest ballot initiative wherein all members write in votes for "a train." This contributed to the accidental election of Alex (radio nickname "A-Train") to the position of Therpston County Aldersm'n. After Alex's election the Pipesmen called for his impeachment on the grounds that their votes shouldn't have been counted in his favor, and that instead they should get to build their train. Secret Pipesmen member Richard "Dick" Therpston III led the campaign for Alex's impeachment; likely because, as Richard Therpston's grandson, he believes the position of aldersm'n is his by rights. The Pipesmen were eventually convinced to call off the impeachment campaign and instead lobby Alex for the project. Said lobbying has included (secretly) purchasing property throughout Nsburg, sending their (secret) demolition brigade to begin blasting for construction, and building a papier mâché train for their (secret) March Marchness parade float. Alex has already vetoed the project despite their efforts, but the Pipesmen seem disinclined to take "no" for an answer.