Skip to Main Navigation
CRABI 12 Month Old Dummy

Description of Dummy Features
The Child Restraint/Air Bag Interaction (CRABI) dummy, was designed to be used in a rear-facing infant restraint positioned in front of a deploying passenger side air bag. A more advanced infant dummy was needed to determine appropriate countermeasures to this potentially dangerous situation. In 1990 the SAE Mechanical Human Simulation Subcommittee formed the Infant Dummy Task Group. The group developed design specifications for three sizes of infant dummies: a 6-month-old, 12-month-old, and 18-month old. The design style was somewhat based on the Hybrid III family of dummies. However the CRABI dummies required response sensitivity while in a rear facing restraint, which is not usually required among larger-sized child dummies. The NHTSA chose the 12month old, since, from the safety perspective, this is the size and weight of an infant becoming a toddler who is switched from rear facing to forward facing child restraints. The protection effectiveness of the child restraint system in that transition mode is of particular importance.

The general shape of the CRABI is based on an infant. The head shape is based on scaling down an adult head. The head is constructed of urethane, with steel inserts molded in for attaching it to the neck of the dummy. The neck used was originally the same as General Motors three-year-old Air Bag dummy neck, but was altered to have extra lateral notches to allow for greater amounts of flexion and extension. The spine consists of a segmented rubber cylinder, spine box and lumbar load cells. The pelvis area is essentially a box that serves as an attachment point for the legs and pelvic accelerometers. The arms and legs mount to the spine box through rubber joints. The skin is a soft self-skinning urethane which can be repaired with adhesive. In addition, the CRABI is capable of collecting up to 34 channels of data.

Comparison of Weight Table
Comparison of Weight, Sitting Height, and Stature for HYBRID III Family
  12 mo CRABI 3 YO Child 6 YO Child 5% Female 50% Male
Weight (lbs.) 22.0 34.2 46.0 108.03 172.0
Stature (in.) 29.4 37.2 47.3 59.1 67.8
Sitting Height (in) 18.9 21.5 25.0 31.0 34.8

Segmented Weights

Segment and Assembly Weight of the CRABI 12 - Month - Old


Weight (lb)

Head 5.79
Neck .84
Torso 8.11
Arms (2) 2.64
Legs (2) 4.62
Total Dummy Weight 22.00


Dimensions of the CRABI 12 - Month - Old

Dimension Description Specifications (inches)
Height 29.5
Sitting Height 18.7
Head Breadth 5.1
Head Depth 6.5
Head Circumference 18.5
Head Height 5.7
Chin to Back of Head 7.2
Chin to Neck 1.9
Head Vertex to Occipital Condyle 4.3
Head Vertex to Head CG 2.9
Head Back to Head CG 3.7
Neck Breadth 2.7
Neck Circumference 8.8
Neck Length 3.3
Shoulder Height (seated) 12.1
Shoulder Breadth 8.4
Shoulder Depth 2.3
Shoulder-Elbow Length 5.9
Elbow-Hand Length 7.8
Upper Arm Circumference at Mid Biceps 5.7
Forearm Circumference 5.7
Chest Breadth 6.2
Chest Depth 4.3
Chest Circumference 18.0
Waist Breadth 5.7
Waist Circumference 17.2
Abdominal Depth 4.8
Hip Breadth (Seated) 6.7
Thigh Depth 2.8
Buttocks - Knee Length 7.8
Buttocks - Sole Length 13.9
Mid-Thigh Circumference 9.2
Calf Circumference 7.1
Ankle Circumference 5.1

Instrumentation Capabilities of CRABI 12 Month Old
Instrumentation # of Channels
Head x, y, z (2) accelerometers 4
Chest x, y, z accelerometers 3
Pelvis x, y, z accelerometers 3
Pubic x and z forces 2
Upper Neck x, y, z forces and moments 6
Lower neck x, y, z forces and moments 6
Shoulder left and right x and z forces 4
Lumber spine x, y, z forces and moments 6
Total number of channels 34

  • Technical Report: Hagedorn, A.V. and Pritz, H.B., " Evaluation of the CRABI 12-Month-Old Infant Dummy and Its Comparison With the TNO P3/4," NHTSA Docket #99-5156, February, 1999.

U.S. Department of Transportation National Highway Traffic Safety Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
1-800-424-9153 (TTY)