[Editor’s note: this story is one of five Coast articles selected as finalists for the 2010 Atlantic Journalism Awards. All five stories are collected here.]
Halifax’s new sewage treatment plant was turned on in
February 2008, and it seemed to fulfill its promised intentions
immediately. All you had to know was that parts of the harbour were
swimmable again, and the most expensive infrastructure project in
Halifax history seemed worth it. By last January, the plant had been
operating almost a year, facing every weather condition without a
hitch. There was no reason to think the heavy rain forecast for
Wednesday, January 14 would prove to be the plant’s undoing.
Until recently, we had no clear idea what exactly went wrong—mayor
Peter Kelly has hidden information on the plant failure behind a wall
of secrecy. He has refused to release a $100,000 forensic audit
investigating the failure, and Tuesday he scheduled yet another
closed-door, no-paperwork council meeting to discuss the sewage
situation.
But over the past several weeks I’ve interviewed engineers from
cities across North America who have explained how their sewage systems
work, as well as many local sources who are familiar with the design
and construction of Halifax’s system. Additionally, officials with the
Halifax Water Commission, who are responsible for fixing the plant,
have recently become more talkative, and are now answering direct
questions. Together, those conversations have led to a deeper
understanding of the plant failure.
What went wrong
Heavy rain alone wasn’t enough to break the plant. In the early
hours of that January morning, a series of cascading mechanical and
electrical problems occurred—a perfect storm of errors. The disaster
started with a Nova Scotia Power failure throughout the north end of
Halifax, including the plant.
The treatment plant is built around an 85-foot-deep “wet well.” A
large tunnel carries Halifax’s sewage—toilet flushes, rainwater,
anything running through the city’s ancient sewer pipes—to the bottom
of the well. Four submersible pumps (and a fifth backup) at the bottom
of the well lift the sewage up to the treatment equipment on the main
floor. When the plant lost its power and the pumps stopped working, a
large iron gate automatically closed over the tunnel, stopping the flow
of sewage into the wet well.
Twenty minutes later, an on-call technician arrived to fire up two
backup generators. With the generators online, the technician opened
the gate and the four pumps began operating. So far, the plant had
responded to the power outage as it was designed to.
But the electrical load from the pumps was not evenly shared by the
two backup generators. One generator carried the load for three pumps,
while the second carried the load for only one pump. The generator
carrying the three pumps overloaded and shut itself down, leaving just
one pump to handle all be rainwater and other sewage coming into the
plant.
The plant couldn’t last long with just one of its four pumps working
off a backup generator.
To stop sewage from coming into the wet well, the gate should have
closed over the tunnel, but the mechanism for lowering the gate was
also powered by the overloaded generator and so didn’t work.
Anticipating just such an emergency, the plant has a switch designed to
shift the gate’s load to the second generator, but this morning it
failed to operate properly. The gate was therefore left slightly open,
and sewage continued to flow into the wet well.
The pump mechanisms and motors are in watertight casings, so they
weren’t in any danger from the rising sewage. However, they are powered
by cables leading from electrical junction boxes placed just 10 feet
above the pumps. The boxes are not watertight. When the rising sewage
reached the junction boxes, it flowed into them, down the electrical
conduits and into the pump casings, shorting out each of the pump
motors, including the motor running the lone working pump. At this
point, even if the power came back on, all the pumps would be
useless.
With no working pumps and the tunnel gate open, sewage continued to
flow into the wet well, rising all the way to “hydraulic grade”—the
level where water pressure evens itself out, in this case sea level,
which is roughly at the ceiling of the plant’s basement. Much of the
plant’s equipment, including the electrical control room and boilers,
were in the basement, below hydraulic grade, and therefore completely
immersed in sewage.
Raw sewage has been flowing into the harbour ever since. City
officials say they can put the plant back in working order by spring of
2010.
How to fix it
Placing the pumps’ junction boxes and the electrical control room
below hydraulic grade was a tremendous design error.
Carl Yates, manager of the Water Commission, tells me that he’ll
have to completely rebuild the electrical control room. There isn’t
space to move the new equipment up to the main floor of the plant, but
he’s confident he can isolate the room from the wet well—that is,
he’ll seal off the room, have its drainage system lead away from the
wet well and lift the electrical cables up over the walls, above
hydraulic grade, before descending again into the wet well.
But Susheel Arora, who heads the wastewater division at Halifax
Water, defends the placement of electrical equipment below hydraulic
grade. Even the quite low placement of the junction boxes—just 10
feet above raging sewage flows—was an acceptable design, says
Arora.
“Lots of operations are set up like this—look at all the plants
around harbours,” he says. Pressed for a specific example, he points to
Toronto, which like Halifax has deep pipes feeding its sewage
plants.
Indeed, many cities, including Toronto, Boston and Portland, Oregon,
have similar “big pipe” sewage systems, but none of those cities favour
using submersible pumps or placing electrical equipment beneath
hydraulic grade. Instead, each uses a “wet well/dry well” design—the
sewage flows into the wet well, but the pumps and electrical equipment
are kept safely isolated in an adjacent dry well.
Toronto’s system does have some electrical equipment below hydraulic
grade, explains Frank Burford, senior engineer with the city of
Toronto, but those are in plants that were designed at least 50 years
ago.
“In new designs all the electric is at grade or above, so you keep
your electrical stuff out of that environment,” he says. Moreover, with
those older inherited designs, Toronto is moving to rebuild the plants
to move equipment above hydraulic grade.
Would Burford design a new system with electrical equipment below
hydraulic grade?
“No,” he says unequivocally.
Yates, for his part, says the junction boxes in the Halifax plant
will be moved above hydraulic grade.
“Those will absolutely come up,” he says.
I had that conversation with Yates on Friday afternoon. Tuesday,
after the closed-door council meeting, the city issued a press release
stating that “all electrical junction boxes will be moving up to the
street level area of the plant with the delivery of longer cables
required to do this expected by the end of August.”
In addition to the design error of placing electrical equipment
below hydraulic grade, there were also at least three problems
associated with the backup generators in the plant: the generators’
powering to the pumps was improperly sequenced, the gate mechanism
switch between the generators failed and the generator overloaded. It’s
unclear at this point if these were strictly design errors or if the
equipment was incorrectly assembled, or both.
One question that needs to be addressed: Why was an emergency
generator that shuts itself down when overloaded put in the plant? Many
emergency generators—for example, those that power fire fighting
equipment—are designed specifically not to turn themselves off
when they overheat; it’s judged better to risk losing a generator than
to lose power to the equipment the generator is attached to.
Regardless, it should be a simple matter to right these
generator-related problems.
Lastly, there’s the tunnel gate, which evidently could not be closed
manually, another clear design error. A weighted, manually operated
gear assembly will need to be installed, so that a technician can close
off the tunnel, even when there’s no power in the plant.
Again, after discussing the gate issue with Yates last Friday, the
city’s press release on Tuesday reflected the gist of our
conversation.
It reads, in engineering lingo: “The sluice gate actuator has
arrived and is being assembled with the gear box.”
Lessons not Learned
It’s tempting to treat the sewage plant failure as merely a narrow
technical problem—discover the mechanical issues involved, fix them
and be done with it.
That’s certainly the view of mayor Peter Kelly, who has repeatedly
said we should “look forward” and “move on” to next summer, when the
plant will again be operating correctly and the harbour once again
clean enough to swim in.
That approach has the added benefit of taking the public focus off
assigning fault for the failure, a politically messy matter of
contention that will no doubt end up in a multi-million-dollar court
battle.
But the sewage plant failure is not just a narrow technical problem.
Rather, the technical problems at the plant were the result of
political and bureaucratic decisions made at city hall years
ago—process issues.
Ignoring those process issues, or hiding them behind a wall of
secrecy, will mean that they won’t be properly addressed, and we’ll
have other catastrophic or costly events in the future.
At its root, the sewage plant failure is a failure in how government
gets stuff built.
Traditionally, when city governments undertook large projects,
they’d hire an engineer to design the project, and then contract with a
construction company to actually build it. The engineer, employed by
the city, represented the city and closely watched to make sure the
contractor built the best possible project. After construction, the
city would take ownership of the project, and city employees would
operate it.
But in recent decades cities have increasingly contracted large
projects out entirely to private businesses—that is, the design and
construction (called “design/build”) and sometimes additionally the
actual ownership and operation (called “design/build/operate”) of the
project is undertaken by private companies.
Halifax’s sewage system was built through a design/build contract
with a consortium of two private firms—Dexter Construction and
Degremont Limited.
“To properly do a design/build—to actually make it work—you also
have to give the operation component of the system to the private
firm,” says Frank Burford, senior engineer for the city of Toronto, who
worked most of his career in the private sector. “Because otherwise the
private companies will do a design/build that is most economical for
them—because that’s what it’s all about, in money—and so redundancy
and extra features that will make it more reliable to operate long-term
can be sacrificed, because their costs end when they turn the keys over
to the owner.
“I found that design/build in Ontario didn’t really work,” he
continues. “You really do need the fingerprint of the owner on the
thing, because then they can review it. It takes maybe a little bit
longer to get something done, and it might cost more, but there’s more
checks and balances.”
Burford points out that whatever cost and time savings Halifax
gained by going the design/build route for the sewage plant were lost
with dealing with the plant failure.
He’s ambivalent on whether cities should stick with the traditional
method of hiring an engineer to represent them in a building contract
or go the opposite direction and contract out in design/build/operate
fashion. Either way, he insists, “operations guys” must be involved in
the design process.
“You get together with the designer of the facility, your operations
people and your engineers in the city,” says Burford, “and you look at
‘what if’—what if this goes wrong, what if this fails, what kind of
contingencies do we have? Then you look at all the Murphy’s Law
stuff—what if, what if, what if, and are we covered for this? So that
at least you can get the system back running.”
Obviously, if such a process happened at all in Halifax, it happened
badly, as the multiple design failures—which one local engineer calls
“boneheaded”—demonstrate.
It’s clear that such a process didn’t work because the city placed
the design of the plant entirely in the hands of the private companies
whose interests laid in cutting costs, and not in providing a fail-safe
plant operational into the future.
A series of mechanical failures didn’t doom the Halifax sewage
plant—the design/build contracting system did.
And yet, the city continues to use design/build contracting for
other large building projects, including the $40 million four-pad
hockey arena slated for Bedford [see correction below], the largest city project to be
undertaken since the sewage system was built.
It’s unlikely that a poorly constructed hockey arena will result in
an environmental catastrophe, but it could very well lead to unexpected
future costs to taxpayers related to shoddy construction.
And if not the hockey arena, then so long as the city relies on
design/build contracting, some other project will fail.
It’s only a matter of time.
Correction, 14 August: City staff informs me that contrary to what I wrote above, the four-pad arena is not a design/build contract but rather a design/build/operate contract. I was given incorrect information by a city councillor, but I should have double-checked. I regret the error.
However, for the record, I also don’t favour design/build/operate projects. I think that either d/b/o OR the traditional method of contracting achieves the desired goal with regard to getting the best project built. BUT, there are, in my opinion, other non-construction-specific considerations; specifically, wage and salary issues. I think that once these sort of projects are completed, they should be operated by well-paid public employees, both because they’ll do a better job than lower paid private employees, and because it’s the right thing to do— government facilities should have well-paid, unionized employees. That’s ultimately a political argument, however, so I left it out of the article. —TB
Animation: How it Broke
Infographic: how it broke
Fig. 1
The plant operating properly: sewage from a deep tunnel enters a wet well 85 feet below the plant. Four pumps lift the sewage to the main floor of the plant, where the sewage is treated.
Fig. 2
A winter storm knocked out power to all the north end, including the Nova Scotia Power feed to the sewage plant. At this point everything worked as it was supposed to: the tunnel was closed off by a gate, and the plant was completely shut down.
Fig. 3
A technician turns on two backup generators and raises the gate.
Sewage flows into the wet well. But the load from the pumps is unevenly distributed between the generators. One overloads and turns itself off. The remaining working generator powers only one pump.
Fig 4
The single working pump can’t handle the volume of sewage pouring into the plant. Sewage rises to the electrical junction boxes feeding the pumps, flows into the junction boxes, down the electrical conduits to the inside of the pump casings, shorting out the motors.
Related Stories
Where the shit flows out
Council’s disaster tourism
What the sewage plant press release misses
Peter Kelly wears the sewage disaster
Contest! Name the sewage plant, win a crappy prize!
The operational loop
Dual methodologies
A man against the people
This article appears in Aug 13-19, 2009.
A sly and unfair dig at the private sector. The dsign build is an approach that gets you what you are willing to pay for. HRM tried to cut costs and because of politics, no private ownership, ended up with a problem.
Design,build, own and operate would have been a better route as long as the plants were constructed to strict parameters.
Access to internal and external correspondence ( not likely) would help us all understand where this went off the rails. My guess is HRM went cheap and got cheap.
As for the 4 pad, you can bet HRM will make all kinds of trade offs to meet a capital budget and not worry too much about operating expenses, they can always jack up the cost of ice time each year. They should have gone with the private proposal and granted the tax break.
You can’t buy a new Rolls Royce for $20,000.
Hey. Great story! Thanks.
The Coast Magazine: never –ever– just sex, drugs and rock and roll.
Please give another example of a large generator in an industrial setting that will run until catastrophic failure. Firefighting equipment is not a valid comparison.
Thanks for finally explaining this. Now, Mr. Kelly, that wasn’t so hard, was it? The video you link to doesn’t work – you might want to check into this. I don’t read this as a dig at all at the private sector. Maybe to Tim’s point, there should be privatized operation with performance penalties in the event errors cause failures.
THE VIDEO IS NOT WORKING!
This is an excellent piece of investigative journalism. Thank you chasing down the story, Tim.
Hi Coast… When you upload a video you must specify that the video can be shared. I have a feeling you have not activated public sharing. Go to your You Tube account or the agency that has shared this video and tell then to disable the privacy setting on this video. My gut tells me the vid was provided by HRM’s communications dept. This would explain the privacy setting snafu. Thumbs up on reporting this video. Visualizations like this can save a few thousand words of explanation
I’ve alerted the web editor to the video problem Thanks for your patience.
www– the paragraph about back-up generators reflects a long discussion I had with an engineer who designs waste water treatment plants. He raised the issue, and I subsequently asked the supplier of the pumps for comment but they haven’t gotten back to me.
I’d say there’s a huge difference between “industrial generators” and “emergency generators.” Clearly, these back-up generators were only to be used for short periods during power outages, not constantly. Regardless, it’s painfully obvious that the generator was too small for the load applied to it. You can address that any number of ways, I suppose– use a bigger generator, change the way the load is allocated, change the tolerance for over-heating, etc. The engineer I spoke with said it shouldn’t have had a cut-off mechanism at all.
Sorry, forgot to make the vid public. My snafu, not HRM’s.
RY2887 sez: “THE VIDEO IS NOT WORKING!”
Must have been a design/build video deal for the Coast.
Running large generators like that without a overload trip would be extremely stupid and dangerous. Instead of talking to one engineer, go look around the province for generators that run without safety trips – you won’t find many…extremely dangerous.
I disagree with the Toronto engineer’s negative view of traditional “design/build” public projects.
However, I agree with the comment that “either way…” (i.e. whether public employees or private companies operate the facility), the “operations guys must be involved in the design process.”
That, to my mind, is the key point of the whole article.
To reiterate, it is not that the “design/build” process is necessarily flawed, but that it wasn’t carried out properly in this case because they didn’t involve public “operation guys” in the process. That’s the lesson here.
differentdrummer is so right. ‘design/build’ is not the problem. You don’t want the local cowboys (engineers) involved in this at all. Because they sure as hell don’t have the experience or know-how to follow the golden rule. Involve experienced operations guys or fail.
This isn’t a bad article, but Tim doesn’t get it in the end, because he’s talking to engineers…
One of the things that I think goes unmentioned in this article is that if the contract had been for a d/b/o then we would likely never know what happened with the plant failure. It is only because this plant is publicly operated and managed that any information is being made public – a private corporation is not accountable to the public and would be able to hide behind lengthy contracts and proprietary legalities. While it seems that the Mayor is being less than open about the problems with this project we know that he is responsible to his taxpayers and if he doesn’t learn from the mistakes then he can be held to account and replaced with someone who will…a private corporation would be much more difficult to deal with not too mention far more expensive…the only ones who benefit from d/b/o projects are shareholders and lawyers.
What does it matter if YOU know what happened? The real issue is in making sure it doesn’t happen again – YOU aren’t part of that process. Neither is Peter Kelly – he has no knowledge of engineering and operations. All he can do is ask for this not to happen again. A private company could be much more efficient, because they are in it to make money, not to have disasters. And for insurance purposes, the facts are going to come out. Take that to the bank.
Tim, I see your amendment –
“BUT, there are, in my opinion, other non-construction-specific considerations; specifically, wage and salary issues. I think that once these sort of projects are completed, they should be operated by well-paid public employees, both because they’ll do a better job than lower paid private employees, and because it’s the right thing to do— government facilities should have well-paid, unionized employees.”
You’re on the right trail there, but still not quite getting it. Here’s the question you need to ask, that nobody really has touched on.
“What was the educational background and work experience of the person called in that evening to fix this problem?”
That’s a start to where your answers lie. Everybody is focused on building a better mousetrap, but currently, the mice are one step ahead (or behind, depending on how you look at things). And until you get the to the heart of the above question, you’ll never understand where the real solution lies, no matter how over-engineered that building is.
Tim wrote: “I think that once these sort of projects are completed, they should be operated by well-paid public employees, both because they’ll do a better job than lower paid private employees, and because it’s the right thing to do— government facilities should have well-paid, unionized employees.”
Uh, aside from the obvious counter-argument to that philosophy, i.e. that well-paid unionized government employees sit on their duffs all day and read the paper because they cannot be fired, wasn’t it a HRM employee who went to the plant that night when all this blew up? Presumably the actions of that person may have a lot to do with why this went down the way it did, and may also go a long way to explaining the HRM secrecy around this.
The key issue here isn’t who is paying the bills. The issue is proper compensation for a well trained and experienced employee. Government/private, union/non-union has nothing to do with this.
To further add to the generator discussion…
I work as a ship’s engineer.
Trust me, if a generator is overheating, and the automatic shutoff is not initiated, the engine will melt within a few minutes. Yes, it will completely melt. So the idea of keeping a generator running when it’s overheating is ludicrous. Generators that have the power to run 4 large pumps like that are also EXTREMELY expensive.
It’s painfully obvious that the generators did not have the power to run the equipment needed to run, and the electricians that wired up the system and allowed for an uneven load between generators are the ones at fault.
Not only can the motor meltdown in a catastrophic fashion, you will most likely be dropping voltage and frequency on the way. That is a disastrous scenario for any plant of this nature. You just don’t do it.
I don’t blame the electricians though – they would just be following engineering plans. It’s the engineers who designed it. And most off all, operations. If the generator is tripping, you start reducing load. That means shutting off auxiliary equipment or one of the main pumps to keep the generator out of overload. C’mon boys, get your act together or this will just happen again, just slightly different…
This is just an amazing piece of journalism. Thanks for putting all the pieces together for us, Tim.
This is a far dry from amazing journalism. The facts were good, kudos there. But the scope of the interviews, and the conclusions and opinions were very poorly researched to say the least.
As a civil engineer directly involved over many years in the design of submersible pumping stations, though not in Canada, I recognise and agree with some important points made by the journalist. However, I don’t agree with his comment that a dry well/wet well system is “better” than having a wet well with submersible pumps. Systems using submersible pumps in wet wells have been used successfully in Australia for many decades. There is no inherent problem with them. Their main advantage is that the installation saves capital cost because there is no need for a second well. Also, pumps are cooled by the fluid in which they are immersed and so ventilation costs are eliminated. “Dry” wells may yet be damp and humid, and corrosion of pipework is then an issue.
I would make sure to involve operators in the design of your systems, because they know what works and what does not. They would have been able to point out the stupidity of having unsealed electrical junction boxes below the possible immersion level. Or was this merely a decision forced on the engineers by the bean-counters, as happens too often?
You should carry out a risk analysis: Develop a risk register, and that includes identifying all possible modes of failure, for all phases of the project (planning, design, construction, operation, demolition), so that you address them and are prepared for them. Document them fully and have them signed off by all stakeholders.
Addressing risks does not mean gold-plating everything. It does mean knowing what they are; their likelihood; what the consequences are if they eventuate; and making a decision on what to do about them. Is it just a simple matter of cost, for example, are you prepared to accept that a part may fail after 10 years? Is it cheaper to replace that part every 10 years than pay much more for a part that lasts 20 years? A lifecycle economic analysis on the major options should determine such matters preferably at the planning stage (before design starts).
(A planning study also is useful to allow the politicians and higher level bureaucrats to see what they can get for their money; or to see what it will cost to provide what they want; before funds are committed. That can save political embarrassment later, and potentially avoids the risk to a successful project caused by underfunding. Was a planning study done for this project?)
Another example: For critical risks, as a designer, you should not be relying on the operators’ level of training. You should “Keep It Simple, Stupid” and design out the risk as far as possible.
Don’t blame the operator if you don’t train the operator. Operators should be intimately involved in the design and commissioning of the system. Commissioning should cover all failure scenarios. Think of the potential reasons why an operator might not be able to address the problem – What happens if the on-call operator is suddenly not available or cannot reach the station? For example, s/he cannot reach the station due to flooding; or has had an accident on the way to or at the station?
It is not about “over-engineering”. It is about providing a facility that works as intended, and being prepared for and knowing how to overcome problems when they occur.
In relation to the risk management, was the electrical engineering design checked and signed off by an experienced engineer? Was the electrical installation checked? The fact that three pumps were attempting to run off one generator points to:
(a) A potential design or drawing fault ( the drawings may not have been checked properly to ensure that each generator only fed two pumps);
(b) A potential installation fault (the electricians installing the wiring did the work incorrectly, and the wiring was not checked once installed).
(c) Even if each generator was assigned to only two pumps, the failure points to a potential inadequate analysis of risk (should there have been a third standby generator to kick in, in the event of one of the duty generators failing? Or should each generator have been capable of taking the full load of all four pumps?
As far as I know, the correction to the article should be corrected. It’s a Design-Built contract. It’s been operated by city employees from Halifax Water.
As far as I know, correction to the article should be corrected. It’s actually a Design-Build project. If not, why have city employees (Halifax Water) been operating it ever since it had been handed over ?
As somebody who knows a bit about this situation, allow me to add to what has been mentioned by Orangecedar:
The issue of involving operators is a real crux, but how will you get experienced operators at the design stage? Not any easy question. Having unsealing junction boxes really isn’t stupid, it’s done everywhere. Why? Because it’s virtually impossible to seal units of that nature. And even if you did, what about the equipment it’s connected to – none of that stuff will run underwater, so why have sealed junction boxes? Flood those motors and instruments, and it’s game over. You’ll just back up into everything anyway.
What an experienced operator would tell you is that you need an overflow with no valve at a level below equipment you can’t live without. Simple as that.
And not blaming the operators. OK, I’m with that so long as they are suited to the job. But now this leads to another issue of which I know more than a lot of other people. HRM designed a pay scale based on WasteWater Treatment education, but was that the appropriate decision? What does a person learn by studying WW treatment? Do they know about motors, pump, seals, common operating issues in a large plant? Can you even teach that? Would a mechanically experienced operator accept that pay? Did HRM understand what kind of expertise they would need to run the plants? There are fundamental questions that need addressing BEFORE hand, these are some of them.
Another question. How in god’s green earth do you think that you could run a plant of that nature without having 24 manning? It’s not possible. So where did the staffing requirements/cost analysis breakdown?
What we will have is an over-engineered plant – they are already moving junction boxes above ground. But have the operations issues been addressed? Without that, you will fail again, and again, …….
I always wondered why there wasn’t a manual shut off valve like you find on old water dam systems. I even wondered at times if it would be possible to find some minutes where someone proposed we save a dollar two sixty by not having one installed because, well, “what are the chances really…?”
Then I read an article in the recent Esquire Magazine on the “Miracle on the Hudson”. That’s the one where Vietnam era pilot dude lands a new Airbus on the Hudson River. Did you know that the Airbus was the first airplane to develop electronic switching devices reliable enough to do away with back-up cable or hydraulic systems? Any feed back pilot guy was getting through ‘the stick’ was put there by the ‘the computer’ more as a security blanket than operating device. Airbus: first time that was tried, worked too.
Is it possible that Karl Hienz Schrieber and Brian Mulroney are some how responsible for the mess in Halifax Harbour??
Just wondering,
Excellent journalism, job well done. Maybe if some of the other media outlets would do some actual work, as was done here they wouldn’t have to cry about declining readership. P.S. the video worked for me.
The authors comments about design/build construction are somewhat off the mark. The main problem was a design error that put equipment at risk. Such an error could have been made on a traditional design/bid/build project at well. The critical issue is that everything breaks eventually and the designer has to plan for those situations. The comments on the generators are also off base. They were correctly designed to shut down before destroying themselves and leading to further expense and delay in resolving the plant problems.
To put it simply…there was no checking to make sure the plans being used were right…as time has proven …!!The overseer must have been one of those secret appointments. And choose well for the job they did….Which was to make sure we got to spend more money…which we have done,and undoubtedly will keep doing.
as a marine engineer, one of our first important lessons is in load-sharing. lt sounds here like someone didn’t know how to properly parallel the gensets, and achieve equal load-sharing. depending on the gear used and the rectifier system, this can be a manual exercise or one which balances automatically, with trips for overspeed, oveload/heat, and redundancy. paralelling gensets is not an easy job. the operator should be onsite, and well-versed in theory and the differing operational requirements of each possible failure. the on-duty engineer must be aware of this at all times, or his training, if any, reflect positively on his experience, fear levels, and when he craps out. he must be present for the entire process, from concept to working solutions. not to worry, son, the flaws were all above your pay grade. just poor engineering from design to installation to start-up to shut-down. can we say:MONEY in unison?