(Bloomberg) -- A possible strike by freight rail workers demanding better working conditions was narrowly averted on Sept. 15, one day before the deadline of a “cooling off period.” The work stoppage would have created shockwaves not only across shipping, but with commuter services as well. Two of the largest rail-worker unions, which represent a combined 57,000 workers, reached a tentative deal on issues such sick leave and pay. The Biden administration was heavily involved in the negotiations, with the last round of talks lasting 20 straight hours.

Why were unions threatening to strike?

Labor unions were pushing for improvements to contracts that have been frozen at 2019 levels, including wage increases and changes to health-care policies. Ten of 12 unions agreed to new deals, but the Brotherhood of Locomotive Engineers & Trainmen and the International Association of Sheet Metal Air, Rail & Transportation Workers held out. The two unions said on Sept. 11 that they were still bargaining over working conditions, and the National Carriers’ Conference Committee, which represents the freight companies, said it was still in “active discussions” as well.

In the tentative deal, unions obtained negotiated contract language exempting time off for some medical events, a core issue for organized labor.

When could a strike have begun?

A strike could have started as soon as Friday, Sept. 16, which marked  the end of the “cooling off” period mandated by the federal government. If the railroads and unions couldn’t come to an agreement, workers might have gone on strike or been locked out by management. The two sides could have also agreed to extend the cooling-off period, averting a work stoppage, but any extensions would have likely been on the shorter side at about 24 hours at a time.

Thursday’s tentative deal extends the “cooling off” period for at least a few weeks, though ratification of the agreement is not certain. Even so, the US Department of Labor called the agreement a “hard-fought, mutually beneficial deal.”

What industries would have been affected?

Roughly 30% of US goods are still transported by rail, so a pause could cost the US economy upward of $2 billion a day. That includes the auto industry: 75% of the new vehicles that are transported by train would be held at the factories. Industries from agriculture to construction would feel the impact of a work stoppage. Corn, wheat, and lumber were among the top agricultural products shipped by freight in the past four years.

Why was Amtrak canceling trains?  

Some Amtrak lines—including cross-country and long-haul services—operate on tracks owned or maintained by freight railroads, meaning they wouldn’t be able to continue if there was a strike. On Wednesday, Amtrak canceled trains going from Chicago to the West Coast, as well as other routes. There was be no impact to Acela service between Boston, New York and Washington. Amtrak says only “minimal changes” are expected in Northeast regional service. 

Amtrak is working to restore normal service. These lines were affected:

  • Southwest Chief
  • Empire Builder
  • California Zephyr
  • Train #421 portion of the Texas Eagle
  • City of New Orleans
  • Coast Starlight
  • Crescent
  • Lake Shore Limited
  • Silver Star
  • Sunset Limited
  • Texas Eagle
  • Auto Train
  • Capitol Limited
  • Cardinal
  • Palmetto (south of Washington)

When was the last railroad strike?

A two-day strike occurred in 1992. It and ended when Congress enacted and President George H.W. Bush signed a return-to-work bill. Strikes in 1922 and 1877 were dubbed the Great Railroad Strike, with their respective years attached.

(Updates throughout to reflect a tentative agreement that was reached Thursday.)

©2022 Bloomberg L.P.