Copiapo, Chile (CNN) -- Rescue officials reported Monday they had to temporarily stop one of two drilling operations to reach 33 men trapped for more than a month inside a Chilean mine.
That effort, known as Plan B, had to stop at a depth of 85 feet (26 meters) because of unspecified problems with a cable, officials said. Drilling should resume within hours, the officials said Monday morning.
Plan B aims to drill at a roughly 80 degree angle into an area of mine shaft used as a mechanical workshop. That distance, engineers estimate, is around 2,030 feet (620 meters).
The drill for Plan B, which is normally used to bore water holes, is untried technology in a mine rescue. The drill arrived Friday and rescuers hope it could reach the miners in as little as two months.
The first effort, called Plan A, involves using a drill placed directly above the shelter where the miners have found refuge. Engineers say the drill would need to reach a distance of about 2,300 feet (700 meters). They have estimated this plan would take between three to four months to complete.
That drill had reached a depth of around 295 feet (90 meters) Monday.
Officials also announced a Plan C on Sunday -- using an oil drill. Although that option could turn out to be the fastest, officials said, it will not be ready until mid- to late September. The drill needs to be transported first from Iquique, a city in northern Chile, and then installed.
All three plans can proceed simultaneously as they approach the mine from different directions.
"We need to have as many options as possible because, as we drill, we encounter problems and we need to have backups," said Laurence Golborne, the Chilean mining minister.
The 33 miners have been stuck inside the Chilean mine since August 5. They were found alive in a shelter about 2,300 feet (700 meters) underground nearly three weeks after a cave-in.
In a separate matter Monday, Minerals Ministry spokesman Nicolas Noman said the families of miners will be allowed to send whatever mail they want. A "resolution had been reached," he said, over complaints from families that some letters weren't being sent down a delivery shaft because they might upset the miners.
Maria Segovia complained to CNN on Monday that some mail she sent did not get to her brother, Dario Segovia.
"It hasn't reached my brother yet," she said. "I delivered a letter to him from our brother William. I sent it Thursday. But so far it hasn't arrived, and my brother is worried. It bothers me because the letters are to make them feel better. Its not right if they don't deliver them."
Asked why the letters had not been sent, she said, "I think they they don't think the letters are very important. But what the don't realize is the letters make them happy, make them feel like their families are supporting them.
"We've asked for an explanation, but the explanations aren't very good. They say we have to let other things be sent, but the letters are tiny. They fit anywhere."
CNN's Karl Penhaul contributed to this report.