Loading a bobsleigh explained: why the driver boards first and the brakeman last, when the crew loads and why it is only trained with a coach on the track.
The honest answer: loading is the moment your crew switches from runners to passengers after the push: the driver first, then the push athletes from front to back, the brakeman last [1][2]. It is not a trick to try on your own but a rehearsed choreography that only develops on an ice track with a coach and a fixed crew.
The running distances explain why the order is fixed. In a two-man bob the driver pushes for only about 20 to 30 metres and jumps in from the left side of the sled. The brakeman runs about 50 metres and jumps in from behind once he can no longer keep up with the speed [1]. The shortest runner boards first, the longest runner last.
The moment comes beyond the crest of the start straight. There, slope and speed already gained add more than further pushing could, and the crew loads without taking speed from the sled [2]. So you jump into a moving, icy machine with spikes on your feet.
Some perspective belongs here: at Olympic Games the injury rate in bobsleigh was 14 to 18 % of athletes, the upper end of the three sliding sports [2]. This guide explains and motivates. It does not replace supervised training or a coach.
The rule: front to back. The driver first, then your push athletes in seating order, the brakeman last [2]. In the four-man the two middle push athletes board between the driver and the brakeman. Milestone: you announce your position and your crew's from memory without thinking. Only then move on.
The driver pushes on the left side of the sled and jumps in there after about 20 to 30 metres [1]. The brakeman pushes from behind, runs longest and also boards from behind [1]. How your jump looks in detail is set by your coach. It is in no text and does not belong in self-study.
You don't jump by feel but together, after the sled has passed the crest [2]. Jump too early and you take momentum from the sled; too late and you chase a bob you will never catch. That is practice, not a study. The crew agrees the signal with the coach beforehand.
Because a mistake here is expensive, there are controlled intermediate steps: sprint drills and heavy sled pushes off-season, and in some training centres start houses with an ice surface where real sleds can be used without a track run [2]. Such centres are rare. So much of the work happens on the track itself, with coach and staff.
After boarding, the push athletes stay in the tub with the head tucked and the trunk strongly flexed [2]. The driver steers under the cowling at the front. Anyone who now adds unrest to the sled endangers themselves and the crew (practice).
Train the role, not only the jump. Before every dry run announce aloud who boards when and where, and repeat the call afterwards: was the order what you announced? This is practical knowledge from dry runs, not a study: crews that run through order and roles aloud beforehand have less confusion in the run. Only the fixed front-to-back rule is documented [2].
The driver. In a two-man bob he runs only about 20 to 30 metres and jumps in from the left side. The push athletes follow front to back; the brakeman boards last from behind because he runs longest [1][2].
Beyond the crest of the start straight. There, slope and speed already gained add more than further pushing could. The crew loads so that as little speed as possible is lost [2].
The push athletes sit with the head tucked and the trunk strongly flexed in the tub; the driver steers under the cowling. The compact position is part of boarding [2].
No. Boarding happens at high speed on ice. You can practise sprint, push and the sequence in dry runs with a coach; actual loading belongs with a club, a track and a crew [2].
Crew Posture in the Bob: Head Down, Body Still, Hands Secure