FAQ #279
F.5.11 External Items

Last Updated On 10/9/2024 08:09:16 PM by

sayovitz

Question
What items are permitted on the outsides of the Main Hoop Braces or the parts Main Hoop above other structures?
Answer
When a wing mount has a single fastener at a Main Hoop Brace node, F.5.11.2.a, that is the best solution. That applies to any external item on the Main Hoop or Main Hoop Braces, such as cameras, which may have additional mounts added next to wing mounts.

Attachments with multiple fasteners per mount or in the middle of the span require low strength fasteners and additional bracing, per SES.

Do not put suspension on the upper portions of the Main Hoop or Main Hoop Braces. Node, YES. Span, NO.

Like the shoulder harness bar (F.6.5.3) there are a few things that are reasonable or permitted by other rules to attach to the Main Hoop and Main Hoop Braces without meeting F.5.11.2, like the head restraint, bodywork, lightweight intake manifolds, manual service disconnect, shutdown buttons.

F.5.11.5 Move these items away from the tubes forward or rearward, so they can’t get driven into the tube wall from the side view or the top.

If something is attached on the side or the back of the car, below the height of the Upper Side Impact or other triangulated structure, we have to make sure it is not fuel or battery or HV or compressed gas. And we have to consider the effects on a corner worker or on another impacting car. But it is generally not a big deal. Even the bottom parts of the Main Hoop are not areas of much concern, though mounting at a node will avoid the concern entirely.

Work on moving motor and accumulator mounts to nodes or other tubes than the MHB and top portions of the Main Hoop. (2025 “should”, 2026 “must”.)
No Attachments

Rule Numbers
2021:2022F.11.