Rescuers in India are gearing up for a challenging rescue operation as they prepare to dig by hand in a bid to reach 41 workers who have been trapped in a collapsed road tunnel for 16 days. The rescue mission, taking place in the remote mountain location of Uttarakhand in the Himalayan state, has been plagued by setbacks, but efforts are now focused on using a traditional mining technique known as "rat-hole mining."

The 4.5km (3 miles) tunnel, located in Uttarakhand state, caved in on November 12, trapping the low-wage workers hailing from India's poorest states. Despite the challenging circumstances, the men have been provided with vital necessities such as food, water, light, oxygen, and medicines through a pipe. However, previous attempts to tunnel through the debris with machines have been unsuccessful due to repeated damage to the equipment.

Now, military engineers plan to employ a group of six skilled workers known as "rat miners" from central India to carry out the hand-digging operation. In this primitive and hazardous technique, the miners will drill from within a narrow evacuation pipe that is 900mm (3 feet) wide. The drilling process will involve one member drilling, another collecting the debris, and a third pushing the debris through a trolley.

While alternative methods, such as drilling a shaft straight down from the top of the mountain, have been explored, the focus remains on clearing the remaining 9 meters (29 feet) horizontally. A separate route to the trapped workers has been opened, with 31 meters (102 feet) of the planned 86 meters (282 feet) already drilled by Monday afternoon.

However, the rescue efforts could be further complicated by unfavorable weather conditions. Thunderstorms, hail, and plummeting temperatures, with a minimum of 9 degrees Celsius (48.2 degrees Fahrenheit), are forecasted in the mountainous region. Nonetheless, authorities express confidence in the skills and adaptability of the rescue team, emphasizing that they are trained to handle various situations.

PK Mishra, the chief of staff to Prime Minister Narendra Modi, visited the site and personally spoke to the trapped workers through a communication link. Assuring them of the ongoing efforts, he reaffirmed that everyone is working diligently to bring them out safely as soon as possible.

The collapsed tunnel is a part of the Char Dham Highway project, a significant venture under Prime Minister Modi's leadership, aimed at connecting four Hindu pilgrimage sites through the construction of an 890km (553 miles) road network.