* Engineers send miners aid down narrow hole
* Miners unaware extraction may take four months
* 'They are strong, they are miners' (Adds new quote, color)
By Alonso Soto
COPIAPO, Chile, Aug 24 (Reuters) - Engineers prepared on Tuesday to install a big drill to rescue 33 miners trapped for 19 days deep in a Chilean mine, and will send down games to help them cope with a wait that could last until Christmas.
The rescue crews began sending hydration gel and medication through a narrow bore hole on Monday to keep the miners alive during the long rescue effort and set up an intercom.
To avoid hurting morale, officials have not yet told the miners how much longer they may be underground.
Engineers must now build a concrete platform and erect the drill, which will bore a shaft 2,300 feet (700 metres) straight down around 2 feet (62 cm) in diameter, and plan to use a pulley to lower a cage to evacuate the miners one at a time. They hope to start drilling the escape shaft by the weekend.
The government has contacted NASA for advice on how to keep the miners healthy with space mission-like rations and help them deal with the extended stay in a confined space. It has also turned to submarine experts in Chile's navy.
Ana Salazar, 51, is sure her son can cope.
"I know he may be down there for a long time, and it will be tough, but he can do it," she said. "We're a mining family, I'm a miner too, so he knows this won't be fast."
The government plans to send the miners card games and dominoes to help them pass the time, and will feed electricity down a small bore hole to run different types of lighting to mimic the sensation of night and day. It is already one of the longest periods trapped miners have survived underground.
Regional superintendent Ximena Matas said it would take a couple of days to assemble the drill. Rescue workers say it will take three to four months to dig the escape shaft.
For a TAKE-A-LOOK [ID:nN22135549]
FACTBOX-Major Chile mine accidents [ID:nN06266599]
For graphic, see: link.reuters.com/kes76n
RELATIVES PREPARE FOR LONG HAUL
The trapped miners' relatives have been living in plastic tents at the mine head in a makeshift settlement dubbed Camp Hope. Maria Segovia, a 48-year-old street vendor whose brother Dario is among those trapped, said she and her siblings would take turns staying at the mine during the rescue.
"It will be difficult to leave this behind, because though it's hard to believe, it has become our home," she said, overlooking a tent where she has slept since the Aug. 5 cave-in. "The wait is different now, though. We are much more relaxed and I know my brother won't crack down there."
"Even though they haven't told them how long the rescue will take, they are strong, they are miners, and they know it won't be easy to get them out," she added.
"This is going to teach the world about survival, about the will to live."
The miners' relatives have sent letters down to the miners, tucked into emergency provisions. Mining Minister Laurence Golborne made the first intercom contact with the miners on Monday.
"We are well. We're waiting to be rescued," Luis Urzua, mine shift leader, told Golborne from below as the trapped miners applauded and sang Chile's national anthem.
Rescuers and family members were heartened by the remarkably good condition of the miners, whose first request was for toothbrushes. The men have stripped off their shirts to help cope with heat down in the mine.
The accident in the small gold and copper mine has turned a spotlight on mine safety in Chile, the world's No. 1 copper producer, although accidents are rare at major mines. The incident is not seen having a significant impact on Chile's output.
In another mining accident in the region, a cave-in at a wildcat gold mine in south Venezuela killed six people and injured two, authorities said on Tuesday. [ID:nN24263878]
The miners in Chile are 4.5 miles (7 km) inside the winding mine. They abandoned a 540-square-foot (50-square-metre) refuge, an area the size of a small apartment, which contains two long wooden benches, opting instead to stay in tunnels because of ventilation problems.
They tried to escape through a ventilation shaft soon after the accident, but found that a ladder was missing. The shaft later caved in.
Ventilation and tanks of water helped the miners survive. They rationed their provisions, eating two mouthfuls of tuna and drinking half a glass of milk every 48 hours. Health officials estimate they may have lost about 17.5 to 20 pounds (8 to 9 kg) each.
President Sebastian Pinera has fired officials of Chile's mining regulator and vowed to overhaul the agency.
Analysts say the feel-good factor of finding the miners alive, coupled with the government's hands-on approach, could help Pinera as he tries to push through changes to mining royalties the center-left opposition had shot down. (Additional reporting by Antonio de la Jara, Simon Gardner, Molly Rosbach and Juana Casas; Editing by Peter Cooney)