Dhutch wrote: Dont have it with me but might post it tomorrow.
This is the draft I have recently written.
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In the invent of incident, the following guide should allow the safe shutdown of the steam plant without prior knowledge of the installation.
1. To suppress and extinguish the fire.
- Immediately close the primary air by sliding the square door shut at the base of the boiler, ensuring the rotary vent in the door is also shut and airtight.
- Close the second air by sliding the vent in the firebox door closed, ensuring the firebox door is also securely closed and air tight.
- In none emergency conditions where time allows, the primary air should be left 1cm open for 2 minutes, before being fully closed.
- In all normal conditions this will extinguish the fire before sufficient water is lost and a critical water level reached.
- No attempt should be made to extinguish the fire using water introduced via the fire door or funnel.
2. To check for a safe water level.
- Steam, and hence water, is released via the safety valves to maintain a safe boiler pressure when steam consumption is unexpectedly reduced by stopping.
- If the water level is visible anywhere within the nearest and smaller sight glass, the water level is within safe limits.
- If the water level is below this, it will most likely be visible within the larger sight glass around the back of the boiler, which shows a red line at the minimum safe level.
- Should water level be in danger of falling below red line on the larger/lower sight glass water should be added with urgency.
- Briefly opening the quarter turn lower (drain) valve of either site glass will eject the glass contents and on closing water will return to the level within the boiler.
- In the event of the water level not be found in either glass, due to significant water loss, the boat should be evacuated and an exclusion zone be put in place around the area.
3. Using/reducing steam
- Steam pressure will not exceed safe levels due to release via the safety valves, however running the engine and propeller can be used to help maintain a safe water level.
- If it is safe to do so the engine can be started and run using the normal controls as previously used, with boat tethered, moored, or moving, and will consume steam in place of the safety valves.
- The further the control valve is opened the faster the engine will run, it can be run at any speed assuming the boat is well secured. The engine cannot be run without the propeller operating.
- Alternatively, the engine room by-pass valve can be used in place of the normal controls. This is the red valve on the pipes leading vertically from the engine.
- The engine driven pumps should then return the used steam to the boiler, maintaining a safe water level within the boiler. See above 'checking for a safe water level'.
- If the engine has been standing for a significant period it may be too cold to start. Operating the reverse lever may cure this, else the cylinder drain cocks can be used to expel condensate.
4. Adding water to the boiler
- If water is low, water can be added to the boiler using the injectors if you are familiar with the operation of steam injectors.
- Alternatively, water can be pumped into the boiler using the manual foot pump on the floor between the engine and boiler.
- If the pump will not depress, the isolation valve between the pump and boiler must be opened to allow the flow of water.
- This has a red handle and can be found by tracing the pipework from the pump to the boiler, open by turning anti-clockwise 4-6 turns.
- Water is drawn from the 'hotwell, the tank on the wall behind pump, the level will drop if pumping is successful, and can be maintained using the 'garden tap' above the tank.
- If for some reason the tap will not maintain the water, water can be added to the tank manually from the canal or river using any suitable container.
- Water can also be added to the hotwell while the engine is running, which will slowly, become introduced into the boiler.
5. Closing down the boiler.
- To isolate the boiler before leaving, each valve should be closed fully by turning clockwise until significant resistance is felt.
- There are four valves on the top of the boiler feeding the engine, whistle, injectors, and domestic hot water cylinder.
- There are two valves lower down, one from the engine driven boiler feed pump, and one from the manual foot pump and injectors.
- The boilers two safety valves cannot be isolated, and the blow-down valve at the rear of the boiler will be shut.
- If water is at a safe level, and the fire is low enough that steam production has ceased and is no longer raising the pressure, safety valves closed, the boiler can be left safely.
6. Closing down the engine.
- The inherent risk from the engine is far less than that of the boiler. The only item that should be closed is the raw water feed to the cooling pump.
- This is the valve mounted to 'mudbox' or grey steel box behind the engine, with a rubber hose on the smaller of the two pumps. It takes around 15 full turns clockwise to close.
- Combined with the closing of the steam supply valve on the boiler (see 'closing down the boiler') the engine is safe to be left.
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The intention was to pitch it at a level which allows semi-competent operators to do something sensible even if nervous or under pressure, while also allowing novices to do the bear minimum to keep it safe, without the word count getting silly, trying to include all conditions the plant may be in at the start of the process, and to foresee the majority of opportunity for it to not go as expected and hence maintain robustness. Prioritising safely, but also not totally excluding maintaining the plant and crafts integrity.
Assumptions made include the incident happening while the boat is moving or shortly after it, and that the majority of systems including the sight glasses are working, as I think its far less likely for the incident to happen during the lighting period, and highly unlikely that the sight glassed will fail during the incident. I have tried to make descriptions as clear to a novice as I can to within reason, while also including the technical terms on the expectation that between the remaining crew its likely there will be an amount of potted knowledge, such as knowing how to turn on the hot water to heater, or knowing what a mudbox is from non-steam boat experience.
The boiler is a vertical fire tube boiler, 200psi working pressure, 600lb/hour and around 3ft dia 3ft height with wet legs, the red line is a inch above the crown (lower tube plate), located in an engine room alongside the boiler, access from the side via a passageway through the room. Main engine controls (regulator and reverser) are in the wheelhouse.
I would be very interested in feedback on the above and any areas people feel I may have missed the mark.
Daniel
