Spelt Flour Bread - Top of Loaf Leans and Splits

Spelt, as you likely know, doesn't have the inherent strength of normal wheats and while being in a pan will help with that, I'd make sure it holds its own when you shape to put it in the pans. If it just flattens right out, it likely needs more tension. 

I'd also consider not opening the oven every 8 minutes and just let it do it's thing after ~ 15 mins of steam. Or not even worry about steam since you're doing a pan loaf. 

By the way, Welcome to TFL.  

What kind of oven are you using?  Is this a regular North-American style home oven with "stove-top burners" where you cook things in pots and pans?  Or is this a counter-top oven with the option to use both upper and lower heating elements?

I'm still thinking you might be using "top heat" in addition to the lower heating element.  If so, that upper heating element may be the cause.

That's great that you have the right oven controls, settings, pieces of equipment, and procedures to make convection mode work for you. Many commercial ovens also work well with convection when baking bread.

But most newcomers here, when using the upper (broiler) element and convection mode in a home oven seem to end up with overly dark tops that set/harden too soon and interfere with expansion.  

"Bottom blow-out" has been a recurring theme on TFL, and is almost always associated with using the upper heating  element and/or convection mode. (A secondary cause of bottom blow-out is too much steam cooling the baking stone from below.)

I also suspect succes vs failure of convection mode may have to do with fan speed, whether fan speed is adjustable, and whether convection mode can be used with only the lower element.   (In some ovens, convection mode may automatically turn on the upper element. Therefore avoiding convection mode avoids the killer "top heat" in those ovens.)

And some convection ovens have only an upper or back-wall heating element, so some kind of cover is needed. 

And of course, baking openly or in a closed vessel (dutch oven, etc) also makes a difference as to whether convection mode can be used to advantage.

So rather than spend days going back and forth trying to figure out how the newbie can configure his/her particular oven and equipment for a successful bake (and many newcomers don't fully understand how their oven works as far as which elements come on, when they come on, when the fan comes on [is it on full time, or only when the heating elements come on] and what that all means in relation to how bread bakes), ...  I find it much easier and faster to help the newcmer get to success by simplifying things and just using non-convection mode.

Most newbies want help in a K.I.S.S. fashion.  And the simplest and quickest way to avoid those dark and early-set tops is to avoid top-heat and to avoid convection mode.

As they advance in their baking skills, and in the understanding of how their oven works, and how all the various oven options/controls work, and equipment options (foil tenting, cookie sheets to block the upper element, cloches, dutch ovens, pans, lidded pans, etc) ... then they can confidently advance to more sophisticated baking.

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I've long admired your bakes. You are obviously a sophisticated baker who is intimately familiar with how your oven operates.  This user wasn't aware that their oven had a lower heating element. They likely aren't going to attain to your level with a just a few back-and-forths of posts/comments.  It takes time, experimentation, etc., but I am confident they eventually can.   In the mean-time... baby steps and K.I.S.S.

Okay, now we're getting somewhere.

Yes, there probably is a hidden lower element.  You can check to see if there is one by setting to pre-heat, and after 30 seconds, place your hand near, not on, the bottom of the inside of the oven to feel if the bottom is giving off heat. You may also be able to see the glowing element through a hole or space between the parts of the lower surface.

Do you have any pans or sheets sitting on the bottom of the oven? If any objects are blocking or interfering with the heat coming from the hidden bottom element, then both elements, top and bottom, would be turning on more than normal.

That top heating element is then "setting" (hardening) the top crust before the dough is done expanding, as Mini Oven points out.

Uncovered loaf bread generally should not be baked with top heat, so you need to figure out how to properly use the bottom hidden element.

Let me know if there really is no bottom element. If there really is no bottom element, then you'll need to figure out how to cover your bread.

Don't assume there is no bottom heating element. You have to know for sure. Check the manual (look it up online) if you have to.

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Added: Ovens that have only a top heating element (or only a back-side heating element) are full-time convection, meaning that the convection fan is always on when the element is on (or still hot).  Therefore, the fact that you can turn convection mode off, is strong evidence that there is indeed a hidden lower element.  Doing the above feel test, or checking the manual, will confirm.

Good luck, amigo.

Perhaps that much dough mass is cooling the oven. That, plus opening the door every 8 minutes, is causing that upper element to come on too much.

It might also work better to bake only 3 or 4 loaves at once so you don't have to rotate so often,  and when you do, you can do it quicker and not lose so much heat.

At least an inch between the pans and the walls is good, but it would help heat/air circulation to have an inch between the pans too.

He best way is to change only one thing at a time, so that you know what made the difference.

Good luck, and bon appétit.