Large TLUD or is it?

[lawry]

I have built a large TLUD and small ones so that I can understand them and obviously use them for what I want.
Here is my question though....
After lighting it the first time, with the subsequent refills the wood sits on top. So is it then BLUD? It still works.
Is it because the wood gas now goes through the hot coal bed?
Or should I be lighting the next batch from the top again? Which means that I must remove the hot coals and put them on top?

[lawry]

Here is the largest one

Blue flames after refilling
vimeo.com/183175385

[Daryl]

Nice

[lawry]

I am staring to understand the TLUD better now. The above picture is of a similar size tlud as the ones I posted before.
I get the blue flames consistently now, even after adding logs.

[lawry]

Here are the flames
youtu.be/SnZon3Zw8-o