Features seen on the Space Shuttle's solid booster; what does "LOADED" mean exactly?

Question

The question Please explain the time reference shown in Shuttle launch engineering video links to the very cool video Ascent - Commemorating Shuttle. After about 22:25 in the video there is footage from "Camera 33" showing the external fuel tank and one solid booster.

As the booster passes by on the right side of the image, I noticed the following sequence of things pass by, superimposed on the otherwise smooth white matte surface of the booster.

Question: What are these, and what exactly does "LOADED" mean?

BLACK band
“LOADED”
BLACK band
WHITE band
(small writing)
BLACK band
“LOADED”
WHITE band
“LOADED”
BLACK band
(small writing)
(Bottom, nozzle)

Answer 1

Image source

The booster has two kinds of joints between its segments, field joints and factory joints. The booster parts shipped to KSC were made up of two segments joined by factory joints. At KSC, these parts were put together using the field joints. There are three field joints and seven factory joints in a Shuttle SRB.

Image Source

Both kinds of joints are pinned joints. As shown in this picture, there are a large number of holes around the joint. Once the segments are aligned, pins are inserted into the holes. Then a retainer band goes around the outside of the joint to hold the pins in.

Here is a cutaway drawing of the factory joint.

Image Source

That's it for the factory joints. These are the black bands you see.

The field joints are assembled basically the same way, but after the retainer band goes around them, electrical joint heaters are attached, to keep the joint O-rings nice and warm and help prevent another Challenger-like failure. (Mechanical features of the field joints are different now from what they were in Challenger days as well.) The white bands are field joints and are bigger because they incorporate insulation and the joint heaters.

Here's a cutaway drawing of the field joints showing the heaters, insulation, retaining band and pins.

Image source

LOADED just means the casing has propellant in it. I haven't found a reference for that one either. But, here is a segment with the counterexample: INERT

Rotated and cropped from this KSC flickr image

LOADED is a segment with real propellant in it, INERT does not have real propellant in it.

Bonus SRB labeling fact: the SRB segment railcars are labeled with DO NOT HUMP.

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That means they should not be subjected to "humping", a process where "rail cars are pushed up a hill (hump), uncoupled, and then rolled downhill into remotely controlled sorting tracks." (source: Union Pacific glossary)

General reference for field and factory joints: SPACE TRANSPORTATION SYSTEM HAER No. TX-116

Answer 2

'Loaded' means it's loaded with propellant (as opposed to something like 'inert' or no marking at all, for casings that have not been loaded). It's used to make it easy to distinguish which casing segments have been loaded with propellant and which ones haven't. Loaded segments require different handling procedures than non-loaded segments.

In the military, color codes are used for the same purpose: to make it easy to distinguish between live missiles (with propellant and explosives on board) and training rounds (without explosives, used to train people in missile handling).

The black bands are a rubber coating over the joints between sections. The white bands are another joint cover, I think. The black ones are applied in the factory, which means the white ones are applied on the launch site when the 4 booster segments are joined. Each segments consists of smaller barrel sections that are joined at the factory before the propellant is cast into the section.

The much wider black band at the top was painted on the left-side booster only to make it easier to distinguish between them during descent and splashdown.