Marnie Surfaceblow: Marnie Finds a Pest

Long-time POWER readers may remember Marmaduke Surfaceblow, a fictional character whose engineering escapades were brilliantly portrayed in hundreds of stories published within POWER magazine’s pages over more than 30 years beginning in 1948. Today, the fictional series continues through Marmy’s granddaughter, Marnie, who is an engineering wiz in her own right.

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Small clues can sometimes help reveal larger problems. Don’t ignore unusual events and remember not to let history repeat.

“One unit’s offline, and it’s about to become two, right as power prices and our customers’ needs hit their peak. You’re going to bloody well make this right, see? I won’t be made redundant over your dodgy equipment!” Plant Manager Terrence “Terry” Stephenson slammed his ham-fist on the conference table, rattling the tea and coffee cups, and startling most gathered in the room.

A calm but iron-hard voice carrying a Maharashtrian accent broke the embarrassed silence. “Sir, I have warned you. Refrain from such outbursts or I will adjourn and end this mediation. This is your final warning. Thank you,” Maya Sharma, lead field engineer of Surfaceblow & Associates International, said.

Stephenson’s furious gaze met that of Maya’s, as she returned his ire with her preternaturally calm stare, dark eyes flashing briefly and giving Stephenson a sudden feeling of being a mouse that had just seen the shadow of an owl pass overhead.

“Sir, our assignment was mediating this disagreement between your power station and Tengu Corporation regarding the failure of two of your continuous emissions monitoring systems [CEMS]. If you are unwilling or unable to mediate in good faith and with decorum, Surfaceblow & Associates International will exit the engagement,” continued Maya.

“Oh, really now!” the incredulous plant manager responded. “And what does your boss think about that, young lady?”

With perfect timing Marnie Surfaceblow, vice president of Surfaceblow & Associates International, strode into the room in her customized, fashionable yet functional, plant coveralls outfitted with arrays of diagnostic and testing equipment in pockets, on her belt, and hanging from lanyards. “Ms. Sharma’s boss is really liking the idea of heading back to London and shopping on Sloane Street for a new purse, because I think it’s time to finally replace ol’ brownie here,” Marnie emphasized by patting her tan leather Prada. “But, seriously, Terry, we’re old friends. Let Maya do her job while I do mine.”

“We need those CEMS working, Marnie. We’re counting on you!” Stephenson emphasized.

“Really now? Oh, and here I thought you enjoyed being off the grid,” Marnie poked. “Never fear! By hook or by crook I’ll figure it out. Maya, where do the negotiations currently stand?”

Maya pinched the bridge of her nose and closed her eyes. “Mr. Stephenson, plant manager, wants a new CEMS, liquidated damages, a five-year warranty extension, and several other items I shan’t list. Mr. Kenji Tanaka, former chief engineer and current head of European sales for Tengu Corporation, is offering to fix anything not functioning on the CEMS, save for negligent or deliberate damage, or be responsible for post-installation modifications.”

Putting a hand on Maya’s shoulder and giving her a comforting squeeze, Marnie whispered, “I know this is your first time, but I also know you can do this. Just try to avoid practicing your Krav Maga on anyone, OK?”

“Yes ma’am. Is jujitsu acceptable?” Maya whispered back with a smile.

CEMS Failures Handcuff Operations

A more composed Terrence Stephenson gave his opinion regarding the CEMS failure. “This waste-to-energy plant is vital for our environmental strategy here in Devon. Landfill space is almost impossible to find in the UK. We recycle everything possible, and still fill our tips. The floods of grockles—tourists—visiting the English Riviera each year bring with them even more waste to dispose of. And being just over five kilometers from the Moors, our plant has stringent limits on stack, effluent, dust, mold, and noise emissions. Oh, you have seen the Moors, right? They’re so lovely in the cold and rain, just perfect if you have extra time on your visit,” he added.

Dodging the question, having already experienced the darkly depressing dreariness of Dartmoor, Maya guided the discourse, “Please describe the events leading to your CEMS failures.”

Pausing to gulp his tea, Stephenson continued, “We have three bubbling-bed boilers, burning everything from plastics and food scraps to hospital waste. Boiler 21 was commissioned in 2014, Boiler 22 in 2018, and Boiler 23 in 2019. The units are identical, as much as possible, part of our plan to both save on operator training and improve safety. They have identical distributed control systems, plant historians, and CEMS. The CEMS were supplied by Tengu Corporation, and they worked—until they didn’t.” Stephenson pointed an accusing finger down the table toward Mr. Tanaka, who sat poised, but clearly concerned. “Will is our senior plant engineer, I’ll let him provide more detail.”

Will Eyre quickly straightened his relaxed posture and began providing his insight. “The CEMS behaved just fine, with no difference between the three units. The plant normally operates at low generation capacity factors, so preventive maintenance is easy to schedule. But the bone-chilling weather this year—normally it never freezes in the southwest—has kept the county well below freezing almost every day. We even set a record low of –20C last month. Most UK homes use gas heat, and demand has been so high that regional combustion turbines can’t start or risk low pipeline pressure. This waste-to-energy plant is critical for grid support, so we’ve been running flat-out nearly all season,” he explained.

“Four weeks ago, Boiler 21’s CEMS failed with no warning. We have one portable testing and monitoring rig for a short-term substitute. Then, a fortnight ago, Boiler 23’s CEMS failed, and we can’t bring it back online. Our testing permit expires in three days, so by weeks’ end Boiler 22 will be the last man standing,” Will said.

“Do you know the root cause of the CEMS failures?” Maya asked.

“It’s isolated to the main CEMS cabinet. We replaced stack sensors, ran new temporary lines from the cabinet to the sensors, new lines back to the DCS, and it’s definitely a flaw in the CEMS. I tell you, Miss Sharma,” Will said. Looking at the floor and shaking his head, he added, “We can’t let this plant go dark or we could bring the whole grid down.”

An Interesting CEMS Layout

A somewhat oversized drab grey CEMS cabinet sat on a concrete pad between two of the plant’s wet scrubbers (Figure 1). As Dan Gibbs, the plant electrical and controls lead, and Victoria “Vi” Lark, the plant maintenance superintendent, cross-checked that the CEMS was powered down, Marnie commented, “It’s like something the aliens from the film 2001 would have made, if they had no taste whatsoever.”

1. Marnie enters the continuous emissions monitoring system (CEMS) shack to begin troubleshooting the equipment failure issues. Source: POWER

Marnie unlocked the inspection door and stoically suppressed shivering, grabbing successive tools to examine the equipment inside. Infrared through ultraviolet lights, magnetic and electromagnetic sensors, and plain-old careful poking and prodding revealed no clues. Dan helped Marnie trace through the P&IDs, while Vi removed a grounded radio frequency shield to allow better access to the CEMS controller internals. Taking a large swig from her two-liter thermos to stop her teeth from chattering, Marnie probed, “This sort of damp cold can really sneak ice into the oddest places. Is there any chance ice expansion allowed water ingress?”

“Not that we’ve found, mum,” replied Dan. “By the way, that coffee smells quite … robust. Did you bring that from the States?”

“No, I just asked the hotel staff to fill my thermos with two liters of espresso,” Marnie replied nonchalantly.

“Beggin’ your pardon for asking, mum, but how are you still alive?” asked an amazed Dan.

“Passion for my work, especially mysteries such as this,” Marnie responded without a hitch. “Say, the wiring from the emissions sensors drops down conduit from two of the three stacks, runs underground to this cabinet, then sends the processed signals on to the control room, yes?” Vi and Dan affirmed Marnie’s supposition. Then, Marnie asked, “Why was the main CEMS hardware moved down here?”

Vi laughed dryly. “Because some bright spark installed the CEMS cabinets high up between the inner and outer stack liners. It’s a mite toasty up there, see, and being so high up, any CEMS controller maintenance required rigging up the crew in a hot, uncomfortable, tight space for hours. And they weren’t happy bunnies about it either,” she said.

Placing a finger on her chin with an exaggerated motion, Marnie frowned. “Why were the CEMS for just Boiler 21 and Boiler 23 moved to this cabinet?” she asked.

“We need at least a month outage to move and test everything, so we wait until our annual boiler outages,” replied Vi. “Boiler 22 is due to move this spring.”

“Curiouser and curiouser!” mused Marnie, continuing her investigation.

Seemingly Minor Equipment Issues

“Everything died at once on the Boiler 21 CEMS,” Will replied to Maya’s question. “Boiler 23 was more gradual. We lost NO _x, then mercury a few days later, and then everything else the following week.”

Maya turned to Mr. Tanaka from Tengu Corporation. “Sir, your opinion on the situation?”

“All CEMS onsite are identical. For Boiler 22 and 23, we offered our newest CEMS at no extra cost, but Mr. Stephenson wanted uniformity for the reasons he gave earlier. Since we had a few of the older CEMS in storage, we supplied those at his request,” Tanaka explained.

“Did the newer CEMS offer critical reliability upgrades compared to the ones installed?” Maya asked while taking notes.

Tanaka shrugged. “Mostly evolutionary technology changes,” he said. “We’d already eliminated mercury across our product line years prior. Mainly we started using solid-state memory instead of hard drives and added a wireless communications package. Just natural progress, like buying a new phone every few years.”

Maya nodded. “Were there any known defects with the original systems?” she asked.

Tanaka shifted in his seat a little, seemingly uneasy. “Our original cabinetry wasn’t as weatherproof as we wanted—one reason we recommended installing them out of the elements, such as in the plant or the stack in a shielded area,” noted Tanaka. “A couple of installations failed elsewhere due to rain ingress, but that was from leaking wiring harness grommets. We sent free upgrades to every site—including this one, which was signed for on July 5th, 2023.”

“Aye, we received them, and installed them to specification,” Stephenson quickly responded. “But we still sometimes found ash in the cabinet, so something was getting in.”

Ash Provides the Answer

Marnie rubbed a glittery, grey-white ash between her fingers and frowned. She showed Dan and Vi what she found, then asked, “I know plant health and safety rules are different in the UK, but I presume smoking on the job is forbidden, correct?”

“Absolutely,” Dan replied. “Barely a soul working here even smokes off the job.”

2. Marnie inspected the CEMS analyzers, and all connections leading to and from the stack and equipment. Source: POWER

“True,” Marnie noted, “this place is so exposed, no one would come out here to smoke.” Poking around further in the cabinet, Marnie muttered her internal problem-solving monologue. “There’s much more ash under Boiler 21’s circuits. It’s everywhere. And this looks sort of like corrosion. Was something leaking into the cabinet?” Marnie peered at the top of the cabinet (Figure 2). “No … and it’s almost like bird lime with the whitish grey, but no sign of any animals getting in here. Not even dust to speak of, other than this ash. So, why is it just ash and not dust too?”

She thought hard, with a half-remembered instance teasing her. The wind picked up, and in the middle of buttoning her windbreaker over her coveralls, she stopped, holding a button that came loose in her hand. Understanding dawned on her face, and she laughed and bounced with glee.

“A countryman of yours, Mr. Sherlock Holmes, studied more than a hundred different types of ash to help him solve mysteries. Well, when it comes to plant engineering, I’m better than Holmes, Dr. Who, and Diana Rigg combined!” Marnie exclaimed. Still beaming with satisfaction, she retrieved a small glass sample vial from one of her many pockets, pinched up a few grams of ash from various locations, and secured the lid. “Right! Let’s return and see how Maya is faring. Knowing her, she cracked this case contemporaneously! Dan, Vi, can I trouble you for a crucible and propane torch?”

Tin Pest?

“Mr. Stephenson, I’ve read the installation manuals, warranties, and contracts, and they clearly state that if the CEMS cabinet or its equipment is moved outside of its original location and exposed to the elements, your warranty is void,” Maya pronounced, dreading the outburst certain to come.

She was wrong, however, as Stephenson produced a printed document. “This came with those new grommets. It says installing them properly not only extends the warranty but voids the prior one. Note this new warranty is rather sparse, saying nothing about the cabinet location,” he countered.

Maya read the new evidence, then turned to Mr. Tanaka. “You are aware of the terms of this new warranty?” she queried.

“Yes, but all warranties we give say the exclusive remedies are replacing defective parts, not damages for lost generation,” replied Tanaka. “We already agreed to replace some failed circuit boards. I could have my team out here by tomorrow, if we can find common ground.”

Maya frowned and responded, “I fear, gentlemen, this has become a question of legalities rather than engineering and science. Thus, I must …”

“Not so fast, my dear Watson!” cried Marnie as she breezed into the room, with Dan and Vi in tow. “It is absolutely a question of engineering and science, as well as history! Vi, could you kindly set up the burner and crucible?”

Vi assembled a burner stand with heat-proof wire mesh, placing a ceramic crucible atop the mesh. A portable propane torch was fixed underneath it, and with the turn of a knob and a strike of the torch flint, in less than a minute flames on low heat were lapping the bottom of the crucible.

“We shall now solve the case of the mysterious CEMS cabinet ash!” Marnie declared, dramatically producing her vial of ash, then dumping the contents into the crucible.

“Now, story time,” she said. “We’re all familiar with tin. After all, it’s been mined in Cornwall and Devon for more than 2,000 years. It can be used for everything from fine jewelry to mundane solder. But don’t let its flexibility fool you; tin is temperamentally temperature transitional. At room temperature, tin is stable in what’s called its ‘beta’ form. Lower the temperature below roughly 13C, and tin’s very crystal structure can change to ‘alpha’ form. Normally, this is glacially slow, if it happens at all, but once it starts, it begins to fall apart with what’s called ‘tin pest.’ And, wow, is it ever a pest!”

After pausing for air, Marnie continued. “Interesting historical sidebar—there’s still debate whether one reason Napoleon’s army suffered defeat during his Russian winter campaign was the crumbling of tin buttons holding the troops’ uniforms together. That may not be proven, but in other cases, we do have proof of tin pest causing havoc. Cathedral organ pipes, beer cooling pipes, Antarctic research equipment, shoot, even the United States tin stockpile started to be consumed by it just a few years back,” she said.

Thrilled by Marnie’s discovery, Maya noted, “Mum, I remember from university, this transformation is very destructive. Alpha tin swells by 25% or more, decaying into an ash-like substance, unless you add lead, of course.”

Turning to Mr. Tanaka, Maya continued, “Your company switched to lead-free solder the year before the CEMS were installed here. It was hailed in your sales literature then for its environmental benefit,” she noted.

“True, but we added bismuth to help slow this transformation. That cannot be the problem,” objected Mr. Tanaka.

“I beg to differ, sir,” said Maya. “Your material safety data sheets show no mention of bismuth. In fact, they say you rely solely upon ‘high-purity tin,’ which in fact is not a reliable deterrent to tin pest. Even using bismuth, it takes care to blend it properly as solder—especially with smaller connections, like circuit boards. Any area not protected adequately and equally would start the transformation.”

Mr. Tanaka was about to respond when Marnie interjected, “The critical component is temperature. Mr. Stephenson—Terry—when you moved the CEMS cabinets out into the yard, you took them from a nice, snuggly, warm environment and put them out in the cold. Remember, if you’re cold, your CEMS is cold. This is why Boiler 22’s CEMS is still running smoothly. And come look, everyone, here in the crucible! The mysterious ash from the CEMS cabinet is now a wee lake of molten tin!”

Amazed conversation filled the room, as everyone crowded around the crucible. Maya quietly sat in intense thought, flipping through her tablet and making notes. Barely five minutes later, she called for order.

Case Settled

“My judgement as arbitrator is first, the solder appears to have suffered from ‘tin pest,’ which was rarely encountered at the time as most solder prior used lead to some extent. Second, the tin pest was accelerated by placing the CEMS cabinet outdoors, exposing it to a much colder environment—again, something not known to be a problem at the time. Finally, some amount of force majeure could apply, as the months of extremely low temperatures recently were both unexpected and likely played a precipitating role,” declared Maya. “Since Tengu Corporation has offered to replace the failed CEMS parts for free, they will do so and add an extended warranty for five more years, which is contingent upon the CEMS cabinets being moved out of the elements and supplied with electric heating, when needed, to a temperature of 15C or greater.”

“I concur!” cried Marnie, as she turned off the propane torch to let the tin cool. Plant staff discussed plans for moving the CEMS cabinet to a warmer clime, and Mr. Tanaka was on his phone ordering replacement gear. Terry Stephenson approached Marnie and Maya, and with deep respect in his voice, said, “I know there’s much to do and agreements to hammer out, but I will say I am impressed. Thank you, both of you, so much. There aren’t any other hidden horrors lurking about, are there?” he asked.

“I haven’t found any large dogs painted with phosphorus or anything like that, but I did notice a hedgehog bearing a certain wicked look,” Marnie laughed. “Anyhow, let’s talk about some scrubber tuning services we could help you out with,” she proposed, looking for her next opportunity to problem-solve.

—Una Nowling, PE is an adjunct professor of mechanical engineering at the University of Missouri-Kansas City.