Why does this occur?

[Manak]

All out of nothing the solid rocket booster just start cliping through the rest of the ship. Does somebody know why?

Video:

[sjwt]

Structural failer, you are going extremely fast in the lower atmosphere, tone down the power on those boosters by at lest 50% or add struts.

[blizzy78]

Press F3 to see the flight log that lists where the failure occurred.

[Smidge204]

The thrust-weight ratio of SRBs goes through the roof as they near empty, which means there's a lot of force on those connections... more force than the current attachment can handle.

Use struts, or use liquid rockets instead of solid boosters, or both.

=Smidge=

[3mon]

Based on the observation of the evidence at hand, we can conclude this is another instance of the typical "NEEDS MOAR STRUTS!" syndrome.

[SRV Ron]

While the acceleration was reasonable, you had a case of compression failure from all of the mass sitting on top of the four boosters. The added acceleration near burnout was enough to cause the failure. Add bracing struts from the top of the four boosters to the side of the short SRB. That should resolve the issue.

[Manak]

Well, i will try some of the suggestions. The problem is that this is in the early part of career, so i dont have struts. Anyways thanks for the help.

[Smidge204]

Well, i will try some of the suggestions. The problem is that this is in the early part of career, so i dont have struts. Anyways thanks for the help.

Then go with liquid rockets, or tweak the boosters to limit their thrust/burn time.

Or spend more time on Kerbin to get the science you need to unlock struts! If you unlocked BACCs then at most you need 63 science, which is not hard to get... a Mk1 capsule with a small fuel tank and LV-30T engine and chute, blast off in a random direction and land in a new biome, Crew report, EVA report, Surface sample, recover. Do that even once for a new biome and you should have enough science for struts!

=Smidge=