Thread by @DerekdotSpace

Saw some concern earlier about SLC-6s flame trench holding up to Falcon Heavy due to Delta IV Heavy having significantly less thrust, I'd like to put that to rest.

That's right, its Flame Trench History Time! (All photos from @SLDelta30 on the National Archive unless noted)

There are currently two flame trenches with three main ducts at SLC-6. The first, currently unused one, is a 90 degree curved duct put in for the Space Shuttle, where the SSME exhaust would be directed to the right side of the stack during initial ramp up.

The second trench, would be a bi-directional duct for the Solid Rocket Motors, splitting each one out into separate directions at ignition. This one was the one used for Delta IV when the launch complex was reconfigured for it.

The SSME duct (left) and half of the SRB duct (right) can be seen here during a fit check of Space Shuttle Enterprise on SLC-6 in 1985. Pretty neat right? So how will this look for Falcon Heavy?

Well the duct likely to be utilized for Falcon Heavy is the old SRB trench, which Delta IV utilized. Delta IV made ~9,420 kN of thrust, but Falcon Heavy makes ~22,800 kN of thrust, more than double the thrust, but not a problem at all for SLC-6 because...

📸 me

SLC-6's main trench was designed to handle >30,000 kN of thrust! The Space Shuttle RSRMs packed some serious heat with each booster making ~13,000 kN each at ignition! (they would top out at ~15,000 kN approximately 20 seconds into flight).

📸NASA/@LaunchPhoto

So all in the SLC-6 flame trench/duct system will absolutely handle Falcon Heavy without a problem thanks to our good friend, The Space Shuttle!