Looking at the video (in part) and assuming that its a current procedure in SA, it is very much more complicated than when regular steam operated on the NSWGR. Depending on the depot and facilities most depots followed a fairly common procedure in light ups. To start with no steam engine could be lit up or an appropriate employee assigned to light up an engine without direct instructions from their supervising officer that being a depot chargeman who had received the all clear from the foreman fitter on duty. The following procedure is what happened at Enfield and likely for years past except for the material used.
The worst day of the week was Sunday afternoons (same at WCK and other major depots as the evening weeks programs were to commence) when to 50 engines were lit up over the next 10-12 hours, more in the early AM mondays with the first around 1430. A list of engines in order to light them up was given to both a firelighter (labourer) as well as two Acting Fireman who had been instructed as part of their ground training on the procedures. Engine list meant they were all ok to light up with only a couple of checks to be done first, it also helped if both were smokers as matches were carried. This is now based on being an A/F working together.
One of the 2 would get a large builders wheel barrow, firing shovel, 2x5 gallon bucket and head to a large bin between the Chargemans office and #2 shed. The bin contained wood shavings soaked in dieseline or other spent waste inflammable liquid filling the barrow and bucket with as much as possible and proceed to the first loco. In the meantime the other A/F would go to the engine make sure the smokebox door was open, check water levels in the gauge glasses, gauge glass was not isolated and at least 1/2 glass of water was showing. We were given kero flare lamps with which to check the smokebox for any issues and the fire box for any leaking stays.
All being ok, the firebox grate area was covered with coal enough to ensure the grate was fully covered, by this time the barrow mate arrived and handed up buckets of the wood shavings, that were tipped onto the shovellng plate, the shavings were then shoveled over the coal to provide a full cover, a last large shovel full was then set alight using the flare lamp, once the shavings were well alight all over the shovel, it was spin shoveled or cut thrown into the firebox in a manner to ensure as large a spread of the burning shavings covered the box. At that point of time the other AF had gone to the next engine on the list to perform the job of in cab duties.
You stayed in the cab until certain the shavings were caught and as soon as being sure you got out quick as the smoke soot and dags were overpowering. The Firehole door had to left completely open to allow for air to flow through. The procedure meant that you would light up at least 1 engine every 10 minutes or more as you had to work between the sheds, mainly 1 & 2 sheds. 2xA/F's started at 1400, 2 at 1500 and 2 at 1600, with 2 non acting Trainee Enginemen at 1600 who had the job of cleaning the cabs. Each type of engine took different times to light up and get steam, from the smallest at Enfield a 30cl through to 32, then standard goods, 36, 38/59 60 in the order of grate area sizes. In order to help getting steam up, during the in cab check the blower was turned on by around a 1/4 turn max, more to help clear the smoke a bit, and not enough to raise steam too quickly and sweat the boiler.
Often, but not always there was a lot of old spent hard cotton waste, that had been through the washing process available, and considered beyond further washing and had been soaked in the dieselene, this was ripped into smaller bits and put on top of the shavings, once it was alight it would usually stay alight a bit longer than the shavings ensuring only a single light was needed.
Within a hour of the first hour of light ups the smoke that started covering the area was incredible by the time the 1400 A/f's had their meal break at 1800-1830 both 1 & 2 sheds were smoke filled, the first engines lit up would be getting steam and you would have been back to put more coal on the areas burnt through
If Garratts were being lit up and being in 3 shed, another shavings bin was there for the procedure which was identical but a much longer process owing to the size of the grate area and to shovel coal from the shoveling plate. What helped here was when they were coaled, as with all engines when the fuelman received the blackout list on the Friday night- Saturday closure was they made sure the bunker/tender at the shoveling plate end was coaled up extra high to keep the shoveling plate covered. Garratts had a fold down shoveling plate that slightly stuck into the cab through the door arch when opened. It was a long throw from there and you usually had to take a step forward with the shovel in order to get the coal over all the grate. The stoker could not be used until at least 60Psi of steam had been reached. A seperate 1600 A/F was assigned to 3 shed for cleaning and maintaining the garratts in steam.
Country depots that did not have access to wood shavings had to have split plank like timbers, these were also soaked in combustible liquids but it took a bit longer as they were a bit harder to light and keep alight. On branch lines were trains went out one day and returned the following day, the loco's carried a pile of timber either on the tender backhead or often seen on 30T class on the front running board and tied down. If shavings were available they were in a bucket carried on the tender. Many of these crews got to learn how to pill bank the engines meaning the wood and shavings were hardly needed the following morning and deemed an insurance, this enabled them to have a full nights sleep and not have to get up and light up again, meaning up to 3 hours extra in bed.
The fire would be knocked out entirely from the front of the box, the rear, under the door was knocked down to half point. With the blower (1/2 turn) left on a bank was filled under the door up to the bottom of the door and it affectively smothered the bottom part of the fire/ash. The coal oozed smoke until the first flames came through at the point above where the fresh piling had taken place at which point the blower was turned off and door shut time to go. The fire was checked as was the water every two hours until before they went to bed. At this point the boiler was filled beyond the top nut and out of sight. Blower on to ensure that burning coal was present, the last fire before bed was to lay some coal on the grate seperate to the bank but make sure the bank was full and a mini shake of the grate to reduce the height, pill again and shut blower and off to bed.
Next morning wake up check the fire. blower on and push the bank forward or what was left of it, it did not take a lot to reset and get burning again, at worst some of the wood was used along with some shavings, this time with blower working and probably minimal steam the wood and shavings readily caught the warm/hot coals and steam raised fairly easily. It was a task but better than a full knock down and warm boiler light up. The danger though could be if one did not know how to do it properly and the boiler stayed too hot water could run out and a boiler burnt.
How its done in these days of modern heritage working is an unknown to me, but the above was how it was in the years 64-73 anyway.