I can appreciate the ability to revert to hand cranking an air compressor, yet I can't help but feel that the 99.99% of events, you'd be better served with keeping a two stroke gas engine ready to go. Air compressors tend to have parts just as or more vulnerable to environmental factors, and you get a lot more power for less elbow grease out of a two stroke.
In 99.99% of real-world scenarios, the rig would have other options to bootstrap a black start—like fully charged air tanks, backup power from a support vessel, or even emergency battery systems. The hand-cranked air compressor is really a last resort tool. We test it during commissioning to prove it could work, but in most cases, it’s never used again in the rig’s working life. It’s there for the rarest situations—like if a rig was abandoned during a hurricane, drifted off station, and someone somehow ended up back onboard without normal support. It’s a true "everything else failed" kind of backup.
Nice to see that at least in some places people are actually thinking to almost-impossible scenarios and taking them into account. I have the feeling that it's quite unlike most infrastructure development nowadays, unfortunately.
The key is the responsible party's skin in that particular game. A drilling rig is a very large, very expensive, and very lucrative man-made island. The backed-up backups have backups. Not only could it be very far away from support vessels, capable of bringing it online in every situation, every minute not in production is money thrown overboard.
Very true, although I think that economic arguments can apply to most infrastructure. What are the actual costs of a day-long nationwide blackout? I have no actual idea, but I'd not be surprised if they exceed 1 billion {EUR|USD}.
The part you are missing is ‘paid by whom’. Unlikely the power companies or regulator is going to be paying that amount here. It’s all the poor saps who didn’t have sufficient backup capacity.
There will be costs/losses by the various power companies which weren’t generating during all this of course, but also fixing this is by definition outside of their control (the grid operators are the ones responsible).
I’m sure public backlash will cause some changes of course. But the same situation in Texas didn’t result in the meaningful changes one would expect.
That’s because there is no effective regulation of the state’s power industry. Since they’re (mostly) isolated from the national grid, they aren’t required to listen to FERC, who told them repeatedly that they should winterize their power plants. And a state-level, the regulators are all chosen by the Governor, who receives huge contributions from the energy industry, so he’s in no rush to force them to pay for improvements.
The real irony was the following summer during a heatwave, when they also experienced blackouts. Texas energy: not designed for extreme cold, not designed for extreme heat. Genius!
Same thing happened in south Texas last year. Years of deferred maintenance on transmission lines resulted in almost two weeks of power outages from two major storms, that could have largely been avoided. The utility provider is mostly allowed to regulate itself (while donating to the campaigns of the dominant political party), and allowed to keep excess profits/return dividends to shareholders, rather than re-invest in infrastructure. There is very little regulatory structure or checks in place to ensure the grid is being maintained. And there have essentially been no consequences, other than an apology and excuses, with an attempt to raise delivery rates even higher. As a home owner, its on me to bear the additional cost of a backup generator, because I can’t rely on the state to regulate the utility to provide the service I’m forced to pay them for.
Based on how difficult it can be to start my chain-saw, snow-blower, and motorcycle after they've sat without being run for a while, I'd not recommend a gasoline-powered engine to be the only thing on stand-by.
Air compressors in adverse environments don't hold up that well either, without basic maintenance. I've had engines run seasonally for decades. It doesn't take much for them to keep working well, though doing nothing at all is an easy way to clog up the carburator.
Compressor pistons/screws that ingest grit/dirt, or aren’t run often enough to boil the water out of them, also tend to not last long. I used to help run a volunteer workshop with an Atlas Copco screw compressor, and it died in a few years because it wasn’t being run hard enough and the screws rusted (doh!).
It shouldn't be that bad. A little fogging oil when put away and drain all the fuel. Then a little starting fluid on the first couple start attempts. Usually they start fairly quickly if they're in decent shape. And that's just for pull starts. My electric start mower starts right up after even 5 months of not running with stabilizer in the fuel.
As an ex small engine mechanic, I'd advise against using a 2 stroke for something like that. A 4 stroke would be a better bet. Better yet would be a natural gas/propane 4 stroke, since gasoline goes stale and plugs carburetors.
Small diesels could be an option but they're harder to pull start for a given size.
> Small diesels could be an option but they're harder to pull start for a given size.
I once needed to jump-start a small marine diesel, many miles from land...
There was a small lever that cuts compression. You have to get it spinning really fast before restoring compression! It's definitely a lot of work!
EDIT - Here is a cheap modern small marine diesel [1]. The operation manual suggests that you don't have to do anything to get it spinning quickly, you just have to crank it 10 times, put away the crank handle, and then flip the compression switch. That's progress!
Lister diesel generators are much the same - half a dozen cranks, restore compression and off they go. The hand cranking can easily break your arm if you get it wrong though.
Even gas engine pull starts have a compression release function built in. That's why you need special cylinder pressure tools to check compression on most pull starts.
I did that too and crank got stuck on flywheel. To stop engine I had to climb over the engine where now-removed stairs were since my mate was clueless. Fortunately the crank handle stayed on.
Cranks and decompression levers are gone for at least 30-40 years now tho.
Not being at all qualified to comment (though I work for a power company), I'd think the hand crank air compressor wouldn't suffer from no spark or bad gas.
If stale gas is a concern, then all of the other steps in-between zero power and your full start are also screwed.
Air compressors have more valves and gaskets that are vulnerable to oxidation, especially in salty environments, so I'd have thought the upkeep between the two, the two stroke would be easier.
But it's an emergency system, not a general operation system. Thus it's not going to be exposed to the salty environment most of the time. You could certainly put the whole thing in an airtight box.
Look at how the military builds surface-based missiles these days: it's in a factory-sealed box. Molten salt batteries so they last for decades. (You don't see molten salt in most purposes because once it's been triggered it's lifespan is in minutes or even less. They're used in applications that only need to deliver power once.)
Diesel will run on mostly anything if it’s running… including methane in the air intake, so you need to think quickly when presented with a generator that keeps running after cutting the fuel
Oil leaking around a turbocharger rotor seal also makes for good diesel fuel, if you define "good" as an exciting uncontrolled disassembly of the engine.
Crude oil from various wells has properties varying from ‘thick, stinky, corrosive goo’ to ‘explosive, barely liquid, bubbly mess’. Also, rigs need to be careful about ignition sources, as methane leaks can be a common emergency condition for some wells/crude.
It’s not the type of thing that using directly is economically feasible, even for emergency situations.
Batteries are great when they have charge. What happens if the generator doesn't want to start the first, second, and third time? How many start attempts do you get before the batteries are dead?
The hand-pumped air compressor is the tool of last resort. You can try an engine start if there's someone there who's able to pump it. You don't have to worry about how much charge is left in your batteries or whether or not the gasoline for the 2-stroke pump engine has gone stale. It's the tool that you use as an alternative to "well, the batteries are dead too, guess we're not going to start the engine tonight... let's call the helicopters and abandon ship"
The data center where I work has large diesel generators for power cuts. They are electric (battery) start. There is no capability to start them manually. The batteries are on maintenance chargers that keep them in good condition. The generators are started and tested every two weeks.
Could the batteries be dead and the generators not start? I guess but it's very unlikely. I get that on an oil rig it might be a matter of life and death and you need some kind of manual way to bootstrap but there's not much that's more reliable than a 12V lead-acid battery and a diesel engine in good condition.
Also, the data center is probably in a city, surrounded by infrastructure that could be used if necessary. An oil rig is in the middle of an ocean, and has to rely on itself.
Lead acid batteries are not exactly what I would call reliable. They require a lot of constant maintenance to ensure that they will work when you need them and they can easily degrade in such a way that they maintain voltage and appear to be good but then fail to deliver the needed amps when you demand them. This is made much worse in cold weather. Finally, if allowed to freeze when they are moderately drained, then the accumulated water inside will freeze and drastically shorten their life span.
I think I'd take Lithium Ion batteries over lead acid for almost every conceivable use-case. They are superior in almost every way. Lighter, less likely to leak acid everywhere, better long term storage (due to a low self-discharge) and better cold weather discharge performance. The only drawback would be a slightly increased risk of fire with Lithium.
I worked with a telecom provider's data center that ended up having a quad redundant diesel generator failure during the first cold snap that took the Texas grid offline a few years back. They had at three fuel supplies gel and then failed to start. The fourth, as I remember, just didn't try to fire.
It's unrealistic, and if one power station is unable to use their batteries to start their emergency generator (through the absurd incompetence you describe, or more likely through a major fire, flood or assault) the grid can be started from a different one.
