Post by dougsanders on May 8, 2014 9:06:45 GMT -8
Igloos are a viable Cascade shelter; however, most climbers are unfamiliar with them. It can take 3 hrs. for a team of 3 to build their first one. With some practice, and reasonable snow, the team can build one in an hour, even less with sticky snow.
This post in intended to provide additional information for chapter writer.
Igloos have advantages. In warmer weather igloos are less likely to collapse than snowcaves. They are not dependent upon a hill with considerable snow depth. Builders stay dryer. Igloos can be build into the summer and tolerate temperatures above freezing. For example, some years ago we awoke to find that our igloo had shrunk during the night. Later we found out the NWS indicated 5 inches of rain had fallen as a warm front passed through. We had slept through the rain.
The Cascade igloo is best sized for 3 climbers. During construction, one climber digs blocks from the quarry which becomes the porch for the entrance, and later, cooking and gear storage area. The second climber transports blocks and helps position them with the third climber who remains inside until the heat-trap entrance is constructed. The inside builder smooths the dome before exiting.
The igloo depicted on page 55 is too large to be built in the Cascades and the walls shown too thin.
An elliptical shape is Cascade standard. The size of the igloo is critical. The inside must not be wider than 6-7 ft. or the roof will be impossibly high to complete and 'rafters' will collapse. The inside length is 6-7 ft. long. The shortest person sleeps in middle to accommodate the entrance opening in the floor. A climber should lie down or use a 6' sleeping pad to measure the size initial size, don't estimate as the tendency is to oversize. Draw the inside boundary in the snow. The smaller the shape is less work and quicker to build.
Smaller metal shovels with slightly curved blades work best for snowcaves and igloos. Saws need to be long, with large kerfed teeth, and sturdy enough to cut through ice layers.
The quarry should start 2 ft. from one end of the igloo. Leave the immediate periphery around the igloo to help the transporter move and position blocks, and to form the tunnel entrance. Generally begin by digging a hole to stand in and enlarge as a wide staircase -sawing multiple blocks the length of each step. Several variations work. The blocks are as long and wide as can be handled. They don't need to be thicker than 8-10in. and can be thinner. Fewer blocks means construction efficiency. Snow is cheap, discard bad layers and blocks.
The spiral upward concept is useful when the snow is not bonding well; gives the blocks gravity assist to stay in place. The spiral is not always necessary. It is more of a upward sloped block than a true spiral. The walls must begin sloping inward by the second tier to assure the final ceiling blocks will be within reach. Bevel blocks to lock them to adjacent ones.
Caulk in only what you have to to support the next block or tier. During construction it will look ugly. After the last structural block is placed, shovel/throw snow onto igloo to fill holes and give it a more conical appearance.
Never needed the water trench or to mark top as described in F8.
In warmer weather it is not necessary to construct the heat trap entrance. Such an igloo provides better wind and noise protection than a tent. It is possible to connect igloos together.
These were built April 26, 2014
This post in intended to provide additional information for chapter writer.
Igloos have advantages. In warmer weather igloos are less likely to collapse than snowcaves. They are not dependent upon a hill with considerable snow depth. Builders stay dryer. Igloos can be build into the summer and tolerate temperatures above freezing. For example, some years ago we awoke to find that our igloo had shrunk during the night. Later we found out the NWS indicated 5 inches of rain had fallen as a warm front passed through. We had slept through the rain.
The Cascade igloo is best sized for 3 climbers. During construction, one climber digs blocks from the quarry which becomes the porch for the entrance, and later, cooking and gear storage area. The second climber transports blocks and helps position them with the third climber who remains inside until the heat-trap entrance is constructed. The inside builder smooths the dome before exiting.
The igloo depicted on page 55 is too large to be built in the Cascades and the walls shown too thin.
An elliptical shape is Cascade standard. The size of the igloo is critical. The inside must not be wider than 6-7 ft. or the roof will be impossibly high to complete and 'rafters' will collapse. The inside length is 6-7 ft. long. The shortest person sleeps in middle to accommodate the entrance opening in the floor. A climber should lie down or use a 6' sleeping pad to measure the size initial size, don't estimate as the tendency is to oversize. Draw the inside boundary in the snow. The smaller the shape is less work and quicker to build.
Smaller metal shovels with slightly curved blades work best for snowcaves and igloos. Saws need to be long, with large kerfed teeth, and sturdy enough to cut through ice layers.
The quarry should start 2 ft. from one end of the igloo. Leave the immediate periphery around the igloo to help the transporter move and position blocks, and to form the tunnel entrance. Generally begin by digging a hole to stand in and enlarge as a wide staircase -sawing multiple blocks the length of each step. Several variations work. The blocks are as long and wide as can be handled. They don't need to be thicker than 8-10in. and can be thinner. Fewer blocks means construction efficiency. Snow is cheap, discard bad layers and blocks.
The spiral upward concept is useful when the snow is not bonding well; gives the blocks gravity assist to stay in place. The spiral is not always necessary. It is more of a upward sloped block than a true spiral. The walls must begin sloping inward by the second tier to assure the final ceiling blocks will be within reach. Bevel blocks to lock them to adjacent ones.
Caulk in only what you have to to support the next block or tier. During construction it will look ugly. After the last structural block is placed, shovel/throw snow onto igloo to fill holes and give it a more conical appearance.
Never needed the water trench or to mark top as described in F8.
In warmer weather it is not necessary to construct the heat trap entrance. Such an igloo provides better wind and noise protection than a tent. It is possible to connect igloos together.
These were built April 26, 2014