A zig-zag kiln is a loop. Green bricks go in ahead of the fire, the fire moves through them, cooled bricks come out behind it, and the emptied space is loaded again. At any moment one part of the kiln is being loaded, another is preheating, another is firing, several are cooling and one or two are being unloaded. Nothing stands still long enough to be written down as a total.
That is why the traditional register struggles with it. A register is a list of days. A zig-zag kiln is a ring of lines, each with its own small history. The question the owner asks is rarely “what happened on Tuesday” and almost always “where is the fire, and what is behind it”.
What a board is
A board is simply the kiln drawn as it is: every line, in order, each coloured by its state. Empty. Loading. Preheating. Firing. Cooling. Ready to unload. Unloading. Tap a line and you see its round: when it was loaded and with how many bricks, when the fire reached it, how much coal it took, when it was ready, what came out.
The colours do the talking. A glance tells you how many lines are ready, how far the fire is from the next loaded line and whether the loading team is keeping ahead of it.
Why the daily register is not enough
Take a simple question: how many bricks are in the kiln right now? From a daily register you need to add every loading since the start, subtract every unloading, and hope nothing was missed. From a board it is the sum of the lines that are not empty. The board answers in seconds and is right whenever the entries are right.
Or: which line did the fire reach on the 14th? The register says coal was burned. The board says where.
The board keeps the entries honest
When every entry is attached to a line, mistakes show up as shapes. A line that is still blue weeks after unloading started was never finished. A line that goes from loading straight to cooling skipped a firing entry. A line with far more coal than its neighbours had a bad night or a wrong figure. On paper these errors vanish into the totals; on the board they are visible, and the health check can point at them.
It also makes coal per thousand possible. Coal is burned by line, bricks come out by line, so the cost of a round is a line’s own story, not a monthly average.
What to enter, and who
The board needs very little feeding:
- Loading: line, green bricks in, date. The loading munshi.
- Firing: line, coal, each shift. The fireman or the munshi on his behalf.
- Unloading: line, bricks out by grade. The nikasi munshi.
Three roles, three entries each, and the board draws itself. The fire position follows the latest firing entry, so moving the fire is nothing more than logging the next shift on the next line.
Lines, chambers and your own numbering
Kilns differ. Some count 22 lines, some 240 sections, some number clockwise from the chimney, some from the loading gate. A good board takes your numbers and your direction and draws accordingly, so the man on the kiln and the owner on the phone are looking at the same thing.
A zig-zag kiln is a machine that runs in a circle. A board is the first record that runs in a circle with it.