Operationally the shipping crisis has been a disaster for the box carriers that underpin global trade: schedule reliability hit a record low of 32 per cent in December, with vessels arriving over a week later than planned on average, according to consultants Sea-Intelligence.

That has caused pain for importers and exporters paying more than ever to wait longer for finished goods and parts, but the congestion has done wonders for the container shipping industry's profitability and balance sheets.

The perennial question occupying the industry - and global economy - is whether the shipping disruption has peaked and how long the journey to something more functional will take.

Lars Jensen, chief executive of consultancy Vespucci Maritime, says the supply chain storm is close to reaching fever pitch - barring any hiccups from coronavirus outbreaks in China to cyber security attacks to critical infrastructure.

"It would appear to me we are reaching the peak of congestion," he said. "It's hard to see it get worse in North America and Europe."

Chinese New Year usually provides the industry with some respite as factories down tools and demand for transporting goods across the oceans experiences a seasonal drop.

But Jeremy Nixon, chief executive of Ocean Network Express (ONE), one of the world's largest container shipping companies, says carriers have not cancelled or "blanked" sailings to ports this year, as they typically do in the weeks after the Lunar New Year.

The intention is to clear the backlogs, he added, but even so, the disruption could run at crisis levels for an extended period before any improvement is noticeable.

"We see a continuation of the same for at least the next three months, and the same in America for longer," he said.

The lack of a discernible trend towards normality is supported by a new indicator, made by Swiss logistics group Kuehne + Nagel. It shows the overall time cargo ships are waiting to berth at major ports around the world taking into account their size. For example, a ship capable of carrying 10,000 TEU, waiting for three days counts as 30,000 TEU waiting days.

"Normal is when a container vessel gets to the terminal and is not waiting. Right now, it's like waiting three or four hours for the gate once the plane has landed," said Otto Schacht, executive vice-president of sea logistics at Kuehne + Nagel.

Parash Jain, head of shipping at HSBC, estimates that container shipping lines will make US$163 billion operating profit in 2022, an 8 per cent increase over last year. This will be "mainly driven by strong tailwinds in contract rates", he says.

However, this week the IMF downgraded the economic outlook for the US and China because of multiple challenges including inflation and record debt levels, raising uncertainty over the continuing strength of consumer demand for goods. A souring of the macroeconomic outlook would be a double-edged sword for the cyclical industry.

"Slower demand is what's needed for the entire logjams to unwind and be less stressed out. But it's also a warning sign," said Peter Sand, an analyst at Xeneta.

"At first it will be welcomed by many in the industry, but then we're looking ahead to the latter part of 2023 and 2024 when carriers add a lot of ships to their networks."