The humanitarian crisis that has seen thousands of refugees migrating to Europe from war-torn countries such as Syria and Turkey has masked risk management challenges and costs for freight transporters and haulers.

Thousands of refugees attempting to board trains and trucks headed for the United Kingdom at the French port of Calais have caused particular headaches for companies seeking to transport goods, sources say.

The legal and moral imperative to save lives in the Mediterranean means shipowners must have procedures to help their crews deal with emergencies, experts say.

Groupe Eurotunnel S.E., which operates the rail and vehicle shuttle tunnel between France and the United Kingdom, said it has spent an extra €13 million ($14.5 million) on security measures in the first half of the year to deal with the refugees.

More than 37,000 attempts reportedly have been made by refugees to breach the tunnel to the United Kingdom.

According to the U.K. Freight Transport Association, Operation Stack — a joint initiative between Kent police and the Port of Dover where trucks are parked or “stacked” on a freeway in southern England to ease congestion at the Port of Dover — cost U.K. freight operators more than £21 million ($31.9 million) following its implementation in July after refuges stormed the channel tunnel entrance in Calais.

As well as the sometimes tragic humanitarian issues, there are very real risks for freight operators, said Peregrine Storrs-Fox, risk management director at London-based freight transport insurer TT Club.

Besides a potential loss of earnings because of congestion and delays at ports, there is a risk of damage to goods and fines for illegal transportation of immigrants if refugees board trucks without drivers' knowledge, he said.

Driver safety also is at risk, he said.

One way to avoid some risks is for truckers to park facing south rather than north to lessen the likelihood that refugees will try to get inside the trailer, Mr. Storrs-Fox said.

Freight transporters should have procedures to help drivers check for unwanted passengers and what to do if they do find them, including contacting authorities, he said.

Forensic firms can assess any damage to goods, particularly perishables, he said, but the ultimate receiver of the goods may reject the cargo, which could spark significant costs and prompt insurance claims, he said.

If a truck inadvertently transports an illegal immigrant, the freight operator could be fined. Such fines are insurable and can be appealed, Mr. Storrs-Fox said, adding that freight carriers should demonstrate that the appropriate steps were taken.

The crisis highlights the need for companies to have sound risk strategies, said Nick Miller, head of fast moving consumer goods at London-based supply chain consultant Crimson & Co.

He said U.K. importers and exporters should look to their U.S. counterparts' example during recent strike-related disruptions along on the West Coast and use several ports. While this might increase costs, it reduces the risk of disruption and helps customer loyalty.

Under the International Convention for the Safety of Life at Sea, ships' masters are obliged to help ships in distress.

Many craft that have been used to transport refugees across the Mediterranean during the crisis typically have been small, overloaded and unsuitable for such passage, protection and indemnity club Skuld said in an advisory to members.

Shipowners operating in the area should be prepared to assist in sea rescues, Skuld said.

“It would be prudent for crews to be briefed on the situation in advance of entering the Mediterranean and for procedures to be discussed and implemented for the eventuality that this type of situation will be encountered,” the marine insurer said.

One step could be to have bottled water, blankets and medical supplies on board, it said. While this may entail extra costs, it also likely would reduce the risks of a rescue operation.

One source, who asked not to be named, said the extra pressure of coast guards in the current refugee crisis has resulted in commercial ships having to take refugees aboard, resulting in cargo damage and delays in delivering the cargo.