We continued on up the road, passing several stretches with deep snow, but none that required digging. Progress was slow as the chains ate their way through the snow and ice up to 2 ft deep.
Then we came to the first real drift. Snow had blown in from the north causing the south facing roadcut to almost completely fill up. The only way to continue would be to dig for hundreds of feet.
The smart thing to do would be turn around and go home. No one ever accused us of being smart. It was only about 10 AM and no one was willing to give up yet. We had the opportunity to try to clear this approximately 300 feet long blockage with slim hope of continuing very far beyond, but, maybe more importantly to us Moggers, we would find out what we and these machines could really do!
The amount of snow to clear was substantial. In many places on this 100 yard long drift, the snow was drifted in to completely fill the road cut, leaving a continuous slope from the mountain above to the mountain below. Cutting a channel just the width of the mogs, even leaving a final depth of maybe 2 ft on the road, would still require shoveling up to 5 ft thickness of laminated ice and snow on the upper side, and a couple of feet on the lower side. That technique would leave 2 ft of road edge plus a snow/ice barrier along the downhill side to provide safety for the trucks.
Our other serious concern was that the hard layers of ice were tilted at near the slope of the mountain. If a truck were on one of those layers, and the slab of ice broke loose, the truck would have no chance to stop. Trenching along the inside edge of the cut would have the truck resting on two different layers. That would also keep the truck tilted toward the mountain and help prevent slipping.
The tendency of the snow to lay in tilted layers is the very reason that snowmobiles and snow cats can't do this job. They could easily slide off the mountain.
Even as several people had already started the shoveling, a group decision was made to start shoveling! Someone was overheard to say "what a beautiful day to dig". We soon found out what the early miners went through. Heavy digging above 10,000 ft elevation was a lot of work!
Two stages of digging were required. The aluminum snow shovels could not penetrate the ice, so first the stuff had to be broken into chunks. Then the chunks could be picked up by hand, or shovel, and thrown off the mountain. The picks from the 'frontier' packages on the Swiss trucks worked well, as did a couple of narrow steel shovels.
Some of those ice chunks continued rolling down the mountain for up to 300 ft, showing just how steep the mountain was at this point. There were no trees to stop a truck. Noticing that situation, someone asked: "what happens if a Unimog rolls off the mountain?". The answer was: "then we know we didn't do it right". We were determined to do things right.
After we had dug maybe 50 ft of 'Unimog ditch' into the drift, Tyson decided to try driving that far. The width of the cut was adequate, and there was little tendency of the truck to dig toward the lower side of the cut. The method looked safe. Tyson did reach the differential-depth limit several times and the bottom of the trench had to be lowered some more (more digging). At this point we had only dug about a third of this drift so Tyson shut it down and we went back to work.
For 4 or more hours we shoveled and rested, and ate...then shoveled some more. Eventually that drift was busted, and the next one too. More winching was required toward the last of the drift, using a big rock as a winch anchor. Tyson made it through, and Rodger followed in his Swissie. Each truck was bottoming out on the differentials so Rodger got a tug from Tyson to get through.
Fred and I with our heavy radio trucks made the decision to stay back where we were and not try the drift. We knew our chained tires would just dig the tracks deeper, we'd high center, and we didn't have enough cable among us to reach the middle of the drift from either end. Not a nice prospect with just a few hours of light left and the other trucks trapped on the upper side.
About that time the word came back from the trucks up ahead that there was another big drift about half a mile up the road. The turnaround decision time of 2 PM was approaching so we knew this trip had achieved all it could do. We had had a good time, appreciated the Colorado high country scenery that few people get to enjoy in winter, and learning more about what our trucks could do.
Even though we had to retreat, the trucks' performance was still amazing. Dr. Stencel commented that Unimogs were still the most cost effective way of extending the season for observatory use.