Kiln Rebuild - Sprung Arch

[artcenter21]

Hey! our larger cone 10 kiln recently suffered some damage where two arch bricks shot through the top and now we are left with a gaping hole. Luckily the keystone was not damaged and every other brick seems to be in the correct spot and undamaged. Though some are sagging and some are pushed up, nothing else happened. I constructed a support for the inside of the kiln so nothing else would shift out of place, but my question is- what is the easiest way to fit those two bricks back into place. I did order a few new arch bricks in case something goes wrong, but it seems like I should just be able to add the new bricks in the existing hole via the top of the kiln, and then shift the sagging bricks back up and all will be good.

Am I under thinking this rebuild? I cannot find any videos or tutorials about how to just add one or two bricks back into an arch. Everything is seems to show the initial build, or small repairs, nothing like what I am about to undertake. 

[neilestrick]

How did two bricks shoot through the top?

You can pull a brick out of the arch and it will remain standing as long as the arch bricks are laid out in a running bond (staggered joints). If that's the case, you should be able to slide the missing brick back into the hole. A little tapping of any loose areas should snug it all back up. The other option is to put the arch form that you used to build the arch back into place, jack the arch up just a little bit, put the missing bricks back in and get everything lined up properly again, and lower the form back down.

[Mark C.]

Yes how did this happen?

I had a few soft bricks spall in half and drop off. I have the arch form still after 41 years and have used it to make repairs (many get rid of the forms) 

This is where a photo taken from inside looking up would really helps us.

I assume these are hard bricks (are they arch  brick and if so what number??)