What weapon is used for these jumps?

The Double-barreled Boomstick, whose recoil boosts the player up onto blocks and ledges.

Walk toward the broken train in the center of the map, then follow the jump descriptions in order.

Are there more than five jumps?

Yes. Two extra jumps were found by the player Tamari in the comments, for seven in total.

KF2 Polar Distress Crash: Boomstick Jump Spots

This short map guide for the Killing Floor 2 Polar Distress event map Crash lists spots where a Double-barreled Boomstick recoil jump lets you climb onto blocks and ledges that are otherwise out of reach. Another take on the same idea is in Polar Distress boomstick jump locations.

Where to begin

First walk toward the broken train in the center of the map.

Starting area near the train Jump 1 setup near the broken train.

First and second jump

There is one to get on top of the block; or you can walk around, get on top of it, and there is another one.

Second jump Boosting up to the second ledge.

Third jump

It is a little to the right of the first jump.

Third jump spot.

Fourth jump

Continue walking to the right from the third jump and take your first left.

Fourth jump spot.

Fifth jump

Walk straight beside the building from the fourth jump and take your first left.

Fifth jump spot.

Two extra jumps

Two more jumps were found by Tamari in the comments.

Extra jump 1 Extra jump one.

Extra jump 2 Extra jump two.

FAQ

What weapon is used for these jumps?: The Double-barreled Boomstick, whose recoil boosts the player up onto blocks and ledges.
Where do I start?: Walk toward the broken train in the center of the map, then follow the jump descriptions in order.
Are there more than five jumps?: Yes. Two extra jumps were found by the player Tamari in the comments, for seven in total.