(NewsNation) — Major ports are at a near standstill from Maine to Texas as tens of thousands of dockworkers strike over wages and the use of automation.

Members of the International Longshoremen’s Association, or ILA, which represents roughly 45,000 workers, walked off the job Tuesday after they were unable to reach a new labor contract with port employers.

It’s the first time the union has been on strike since 1977 — a standoff that could cost the U.S. economy $540 million per day.

The ILA is asking for significant wage hikes and a total ban on automated cranes, gates and container-moving trucks.

“We are prepared to fight as long as necessary, to stay out on strike for whatever period of time it takes, to get the wages and protections against automation our ILA members deserve,” ILA President Harold Daggett said in a social media post.

Here’s how much longshoremen currently make and what they’re asking for going forward.

How much do longshoremen make?

Under the contract that expired Monday, top-scale port workers earned a base pay of $39 an hour, or just over $81,000 a year. That rate applied to workers with at least six years of service.

The starting pay for dockworkers was $20 an hour, which rose to $24.75 after two years and $31.90 after four years.

However, many longshoremen make much more with overtime and other benefits.

A 2019-2020 report by the Waterfront Commission of New York Harbor said about a third of longshoremen based there made at least $200,000 a year, and more than half earned over $150,000.

Though not the norm, 59 dockworkers brought in more than $400,000 that year, according to the report.

The ILA points out that many workers operate multimillion-dollar container-handling equipment for “a mere $20 an hour” and says most members are constantly on call.

“They work extraordinary hours, sacrificing time with their families,” the union said in a statement.

Daggett made over $900,000 last year — $728,000 from the ILA and an additional $173,000 for being the president emeritus of ILA Local 1804-1, according to union filings with the Department of Labor.

West Coast dockworkers have a separate union from East Coast workers. They agreed to a new six-year contract last year, which included a 32% raise, Reuters reported. 

According to The New York Times, West Coast longshore workers make nearly $55 an hour, earning an average of nearly $220,000 last year.

What is the union asking for?

The union is demanding a 77% raise over six years — a $5 increase per hour for each year of the contract. That means the top-scale hourly rate could reach $69 by 2030 — over $140,000 a year.

“Our members feel underappreciated, especially given the sacrifices they made during the pandemic, keeping ports open and the economy moving,” the union said in a statement Monday. “The wage increases in the previous contract were rendered meaningless by rising inflation.”

The ILA is also asking for better benefits and a ban on automation over concerns that new technology will threaten jobs.

The union said foreign-owned ocean carriers “continue to make record profits” and are imposing “outrageous surcharges on consumers.”

The U.S. Maritime Alliance, the group negotiating for the ports, said it’s offered a nearly 50% wage increase and called the strike “completely avoidable” in a statement.

The ILA has rejected that offer and said it doesn’t address worker demands. The union reiterated that it’s against any form of automation that replaces jobs or historical work functions.

The Associated Press contributed to this report.