Section 1: Introduction
1.1 Overview and Governing Body
Bobsled (also known as bobsleigh) is governed by the International Bobsled and Skeleton Federation (IBSF), founded in 1923 and headquartered in Lausanne, Switzerland. The sport operates under the IBSF International Rules, updated annually. The IBSF also governs skeleton, making it the authority for two of the three Olympic sliding disciplines (luge falls under the FIL).
1.2 Olympic History
Bobsled has been part of the Winter Olympic programme since the inaugural 1924 Chamonix Games, making it one of the original Winter Olympic sports. The four-man event has been contested since 1924, two-man since 1932, women's two-woman since 2002 (Salt Lake City), and women's monobob since 2022 (Beijing). The sport was absent only from the 1960 Squaw Valley Games, where the organising committee deemed the cost of building a track prohibitive.
1.3 Discipline Overview
Bobsled is a gravity-powered sport in which crews of one, two, or four athletes pilot an aerodynamic sled down a purpose-built ice track. The sport combines explosive sprint power at the push start with the pilot's precision steering through high-speed curves. Top speeds routinely exceed 150 km/h (93 mph) in four-man events, with G-forces reaching 5G in banked curves.
Section 2: Equipment
2.1 The Sled
Bobsleds are precision-engineered machines constructed primarily from steel and fibreglass composites. Key specifications vary by event:
- Monobob: Standardised IBSF-supplied sled, weight 162 kg (357 lb). All athletes use identical sleds to equalise equipment, making the event purely about driving skill and athleticism.
- Two-man/two-woman: Maximum sled weight (without crew) 170 kg (375 lb). Maximum combined weight (sled + crew) 390 kg (860 lb) for men, 340 kg (750 lb) for women. Maximum length 270 cm (106 in), maximum width 67 cm (26.4 in).
- Four-man: Maximum sled weight (without crew) 210 kg (463 lb). Maximum combined weight (sled + crew) 630 kg (1,389 lb). Maximum length 380 cm (150 in), maximum width 67 cm (26.4 in).
Teams below the maximum combined weight may add ballast to the sled, but all added weight must be securely fixed inside the sled body and declared at inspection.
2.2 Runners
Each sled rides on four steel runners — two front (steerable) and two rear (fixed). Runner specifications are strictly controlled:
- Material: steel with a minimum Rockwell hardness of 63 HRC
- Runner gauge (width between opposite runners): 67 cm (26.4 in)
- Runner temperature: must not exceed ice surface temperature by more than 4°C (7.2°F) at the time of pre-race inspection. Heating runners artificially is illegal and results in disqualification.
- Runner profile: standardised profile templates are provided by IBSF; custom grinding is permitted within tolerance.
2.3 Crew Equipment
- Helmet: Full-face helmet mandatory for all crew members. Must conform to ECE 22.06, Snell SA2020, or equivalent standard approved by the IBSF.
- Speed suit: Skin-tight aerodynamic racing suit. Maximum material thickness is regulated. No artificial aerodynamic aids, fins, or protrusions are permitted.
- Start shoes: Spiked shoes for the push start, with a maximum of 44 spikes per shoe. Spike length maximum 5 mm (0.2 in). Shoes must be IBSF-approved to ensure consistent traction on the ice start ramp.
- Gloves: Mandatory for all crew members. No grip-enhancing substances permitted on glove surfaces.
Section 3: Playing Area
3.1 Track Specifications
Bobsled tracks are purpose-built, artificially refrigerated ice channels. Track construction uses reinforced concrete with embedded ammonia or brine refrigeration pipes to maintain ice temperature. Key dimensions:
- Total length: 1,200–1,650 m (3,937–5,413 ft)
- Vertical drop: 100–150 m (328–492 ft)
- Average gradient: 8–15%
- Number of curves: 15–20, including at least one labyrinth (S-curve combination)
- Minimum curve radius: 20 m (66 ft)
- Wall height in curves: Up to 6 m (20 ft) in high-speed banked sections
- Ice thickness: 3–5 cm (1.2–2 in) on the refrigerated concrete surface
3.2 Start Zone
The push-start zone is approximately 50 m (164 ft) long with a gentle gradient of 2–5%. The surface is ice-covered, and crew members use spiked shoes for traction during the sprint. Electronic timing begins when the sled breaks the first light beam. Separate start positions exist for different events: four-man and two-man typically start from the top, while women's events and monobob may start from a lower position depending on the track.
3.3 Finish Area
The finish area includes a deceleration straight of at least 100 m with gradually increasing incline to slow the sled naturally. A mechanical braking area follows. Electronic timing beams capture finish time to 1/100th of a second. The finish zone must accommodate sled retrieval and provide safe exit for crew members.
3.4 Notable Olympic Tracks
There are fewer than 20 active sliding tracks worldwide. Notable venues include the Yanqing National Sliding Center (2022 Beijing), Alpensia Sliding Centre (2018 PyeongChang), Sanki Sliding Center (2014 Sochi), and the historic St. Moritz–Celerina Olympic Bobrun — the only remaining natural ice track used for international competition.
Section 4: Players & Officials
4.1 Crew Positions
- Pilot (driver): Sits at the front of the sled and steers using two D-shaped rings connected by cables to the front runner axle. Precise steering inputs determine the sled's line through each curve. The pilot is the only crew member who actively controls the sled during the run.
- Brakeman: Sits at the rear of the sled. Operates the rear brake lever but may only apply it after crossing the finish line. The brakeman is typically the strongest pusher and loads last during the start.
- Pushers (four-man only): Two middle crew members who contribute to the push start and then tuck inside the sled. They provide additional mass and help stabilise the sled through weight distribution.
4.2 Crew Requirements and Athletics
All crew members must be of the same nationality for Olympic and World Championship events. Mixed-nationality crews are permitted in lower-tier IBSF competitions. Monobob is a solo event requiring the pilot to push and drive alone. Each national federation may enter a maximum number of sleds per event as determined by IBSF ranking quotas.
Bobsled crew members are among the most powerful athletes in winter sports. Many are recruited from track and field (sprinters, shot putters) or American football due to the explosive speed and strength required for the push start. The 50 m push phase on ice demands a combination of top-end sprint speed and the ability to generate force against the sled while maintaining balance on a slippery surface. Elite two-man crews complete the push in under 5 seconds; four-man crews in under 4.8 seconds.
4.3 Officials and Jury
- Race Director: Overall authority for the competition. Responsible for start order, weather decisions, and race conduct.
- Technical Delegate: IBSF-appointed official who ensures compliance with all technical regulations, including sled inspection and runner temperature checks.
- Track Chief: Responsible for ice conditions, track safety inspections, and curve maintenance.
- Start referee: Supervises the push-start zone and signals any false starts or violations.
- Timing officials: Operate the electronic timing system, recording start time (50 m split), intermediate splits at designated curve markers, and finish time to 1/100th of a second.
Section 5: Rules of Play
5.1 Competition Format
Olympic and World Championship events consist of 4 runs over 2 days (2 runs per day). World Cup and lower-tier events may use 2 runs in a single day. The combined cumulative time of all runs determines the final ranking. Monobob follows the same format.
5.2 The Push Start
The push start is one of the most critical phases of a bobsled run. Crew members sprint alongside the sled for approximately 50 m on the ice surface, pushing the sled to build maximum velocity before loading in sequence. The pilot enters first, then pushers (four-man), and the brakeman loads last. Start time — measured from the first timing beam to a point approximately 50 m down the track — is a primary competitive differentiator. A difference of 0.1 seconds at the start can translate to 0.3 seconds at the finish.
5.3 Driving and Steering
The pilot steers using two D-rings connected by pulley cables to the front runner axle. Steering adjustments must be subtle — overcorrection scrubs speed by increasing friction between the runners and the ice wall. The ideal line through a curve enters high, crosses the apex at the lowest point, and exits high to carry maximum speed. Pilots study track geometry extensively and memorise optimal lines for each curve during training runs.
Different curve types demand different techniques. In a high-banked Kreisel (360-degree loop), the pilot must commit early to a high line and maintain steady pressure. In a labyrinth (rapid S-curve combination), quick transitions between left and right steering are critical. Straight sections between curves require the pilot to centre the sled and minimise runner contact with the walls, as even light wall touches create significant time losses. At 150 km/h, the pilot's reaction window is measured in milliseconds.
5.4 Braking Rules
The brakeman operates a serrated metal brake located between the rear runners. The brake may only be applied after the sled crosses the finish line to decelerate in the braking zone. Applying the brake at any point before the finish line results in immediate disqualification for that run. In an emergency (e.g., a crash or imminent danger), the brake may be applied without penalty at the race director's discretion.
5.5 Monobob Specifics
The monobob event, introduced for the 2022 Beijing Olympics, uses a standardised sled provided by the IBSF. All pilots race in identical equipment, eliminating the technology advantage that wealthier nations enjoy in two-man and four-man events. The pilot pushes the sled alone from the start, loads in, and drives. Monobob push starts are shorter and slower than crewed events because a single athlete generates less force. The event has been praised for expanding access and making bobsled more equitable across nations.
5.6 Training Runs
Before competition, crews are allocated a set number of official training runs (typically 6 training heats, sometimes divided over 2–3 days). Training runs allow pilots to learn the track geometry, test different steering lines, and build confidence at progressively higher speeds. Start-order for training runs is rotated to give all crews exposure to different ice conditions. Timing data from training runs is published but does not affect competition seeding.
5.7 Start Order and Seeding
Start order for the first run is determined by IBSF World Rankings (highest-ranked crews start first to benefit from optimal ice conditions). For subsequent runs, the start order is reversed based on current standings — the last-placed crew goes first, and the leader goes last. This gives trailing crews an advantage of fresher ice.
5.6 Weather and Cancellation
The race director may postpone or cancel runs due to excessive wind, precipitation, warm temperatures degrading ice quality, or unsafe visibility. If fewer than the scheduled number of runs are completed, results stand based on completed runs (minimum 2 runs for a valid result).
Section 6: Scoring
6.1 Timing and Rankings
All times are recorded electronically to 1/100th of a second. The final ranking is determined by the cumulative total time across all completed runs. In the event of an exact tie in total time, the tied crews share the same placement (both receive identical medals at the Olympics).
6.2 Split Times
In addition to start and finish times, intermediate split times are recorded at designated points along the track (typically 3–5 splits). These help analysts assess where time is gained or lost and are broadcast to spectators in real-time.
6.3 Tie-Breaking
In the event of an exact tie in cumulative time (to 1/100th of a second), the tied crews share the same placement. At the Olympics, both crews receive identical medals. This has occurred at multiple Olympic Games, most notably in the 2014 Sochi two-man event and the 1998 Nagano two-man event.
6.4 World Cup Points
In the IBSF World Cup circuit, crews earn points based on finishing position (1st = 225 points, 2nd = 210, 3rd = 200, descending). Cumulative World Cup points determine the overall season standings and influence seeding for the following season. The top-ranked crews on the World Cup circuit earn quota spots for their national federations at the World Championships and Olympics.
Section 7: Violations & Penalties
7.1 Disqualification Offences
- Brake applied before finish: Disqualification for that run. Time is voided.
- Runner temperature violation: If runner temperature exceeds ice temperature by more than 4°C at pre-race inspection, the crew is disqualified for that run.
- Overweight sled: Combined weight exceeding the maximum limit results in disqualification.
- Equipment modification after inspection: Any alteration to the sled, runners, or personal equipment after official scrutineering results in disqualification and potential further sanctions.
- Unauthorised substances: Use of any friction-reducing substance on runners (beyond standard polishing) is prohibited and results in disqualification.
7.2 Start Violations
- False start: Crews are allowed one false start. A second false start results in disqualification for that run.
- Late start: Crews must begin their push within a specified time window (typically 60 seconds) after being cleared by the start referee. Failure to start results in a DNS (Did Not Start) for that run.
- Push zone violation: All crew members must be aboard the sled before it exits the designated loading zone. A crew member who fails to board or falls off during loading results in disqualification for that run.
- Assistance: No outside assistance (pushing, touching, or stabilising the sled by non-crew members) is permitted after the start command. Officials positioned at the start may steady the sled before the command but must release on the start signal.
7.3 Post-Race Violations
- Sled modification discovery: If post-race inspection reveals equipment changes made after pre-race scrutineering, all results from the affected run and subsequent runs are voided.
- Weight discrepancy: If the crew + sled combined weight is found to exceed the maximum limit at the post-race weigh station, the run is disqualified. Crews who are found to be underweight are not penalised (lighter crews have no unfair advantage).
7.3 Behavioural Infractions
Unsportsmanlike conduct, interference with another crew's equipment, or failure to comply with official instructions may result in fines, suspension from subsequent races, or referral to the IBSF Disciplinary Commission. Teams may protest technical decisions within 30 minutes of the official results being posted, accompanied by a protest fee.
Section 8: Safety Considerations
8.1 Track Safety Features
- Track walls are constructed of reinforced concrete with smooth ice surfaces to guide the sled. High-speed curves are profiled with steep banking to contain sleds under high G-forces.
- Overflow lips (raised edges) at the top of curve walls prevent sleds from leaving the track.
- Speed-reducing chicanes or deflection walls may be installed at dangerous sections if track speeds exceed design parameters.
- Run-off areas and deceleration zones are provided at critical points, particularly after high-speed curves.
8.2 Crew Safety
- Full-face helmets are mandatory for all crew members during training and competition.
- Crews must complete a minimum number of training runs on a track before competing (typically 3–6 training heats).
- Novice pilots must progress through lower-level IBSF licensing before competing at World Cup or Olympic level.
- G-forces in high-speed curves reach 4–5G, requiring crew members to brace with neck and core muscles to prevent injury.
8.3 Medical Provisions
A medical team with sled-mounted stretcher capability must be stationed at the finish area. Additional medical spotters are positioned at high-risk curve locations. Ambulance access to the track must be available within 3 minutes at any point. All crew members undergo mandatory medical examinations before each competition season. The race director has authority to cancel or delay runs for safety reasons at any time.
8.4 Crash Protocol
If a sled overturns during a run, crew members must remain inside the sled (or as close as possible) and allow the sled to slide to a natural stop. Standing or attempting to exit a moving overturned sled is extremely dangerous. Track marshals clear the track and assist crew evacuation. A crashed sled may continue competition in subsequent runs if it passes post-crash technical inspection.
8.5 Environmental and Ice Conditions
Ambient temperature, humidity, wind speed, and precipitation are continuously monitored by track officials. Ice surface temperature is measured at multiple points along the track and recorded before each run. Warmer conditions soften the ice, increasing friction and slowing times, while extremely cold conditions can make the ice brittle and unpredictable. If air temperature rises above approximately 5°C (41°F), the race director may shorten the competition window or cancel runs to protect ice integrity. Fog and heavy snowfall can impair visibility and lead to race suspensions.
8.6 Sled Inspection and Anti-Tampering
Pre-race and post-race sled inspections are conducted by IBSF technical delegates. Inspections include verifying sled weight (with and without crew), measuring runner temperature using calibrated infrared thermometers, checking runner profile against IBSF templates, and examining the sled for unauthorised modifications. Runner polishing compounds are regulated, and teams may only use approved substances. Any crew found with prohibited heating devices, aerodynamic modifications, or weight concealment faces immediate disqualification and referral to the IBSF Disciplinary Commission.
