Peril of the Month: Gas Supertankers
Ingram, Timothy H.
Peril of the Month: Gas Supertankers by Timothy H. Ingram With environmentalists pushing for increased use of pollution-free natural gas and shivering schoolchildren agreeing with the...
...Protecting the shoreline was the right idea, but moving the tanks closer to people suggests a strange trade-off between scenery and safety...
...To move the gas from Murmansk on the Barents Sea to the East Coast of the U. S., and from the Eastern Siberian plateau to West Coast ports, would require a fleet of some 30 LNG tankers...
...Researchers discovered that LNG, when- thrown on water, could "explode" with a flameless but awesome boom...
...At normal temperatures, natural gas (methane) is lighter than air, but as it poured out of a tanker at temperatures around -260 degrees Fahrenheit, it would form a dense, heavier-thanair blanket...
...But the grandiose plans being laid for LNG shipments have caused concern even in the industry itself...
...Crew members had disguised the leak by purging the area surrounding the tanks of LNG vapor with inert gas, so the monitoring devices had reported no methane presence when later tested by Coast Guard inspectors...
...Crews usually don't keep logs or records of readings...
...As G. H. Martin explained: "We stuck our necks out and said, look, there's an energy shortage...
...The gas had to be confined at -259 degrees Fahrenheit-a temperature that cracks even steel like glass...
...The skeptical locals then insisted that Fetteroll demonstrate outdoors, where, as the local papers reported, "the vapors ignited instantly into a small fireball...
...Lester Wolff of New York called last fall for a halt to LNG-tank construction in populated areas...
...There was some talk of explosion, but it seemed unlikely as long as oxygen was kept out of the gas tanks...
...The fiery destruction of an LNG tanker is bad enough, but it is even more troubling to think that the gas cloud could blow up or burn after drifting into a city...
...Vapor Cloud: Here the options multiply and the possible range of disaster is more widespread...
...There, it could surround the leaking vessel in burning seas...
...Once in the confined space of the sewer pipes, the quickly vaporizing, burning liquid gas exploded with tremendous force...
...The dealings have cooled off slightly under White House scrutiny, but a U. S. decision on the deal is expected this spring...
...Not that LNG is the only dangerous cargo afloat: naphtha, ethylene, and liquefied propane gas (LPG) are also carried in bulk and are also fire hazards...
...Peril of the Month: Gas Supertankers by Timothy H. Ingram With environmentalists pushing for increased use of pollution-free natural gas and shivering schoolchildren agreeing with the international oil companies that an energy crisis is on the way, a whole new chapter in ocean commerce has begun: the massive importation, in fleets of supertankers, of liquefied natural gas (LNG...
...It is important that the general decisions be made, and that we examine alternatives before welcoming fleets of LNG tankers...
...What resistance there has been to LNG plans has come mainly from those who live next to the tanks and ports...
...The captain was told he couldn't unload until a shore repairman came out and fixed the defective system...
...But they showed us a movie where they stuck a fireman's rubber boot into LNG and the bottom froze and cracked off when they picked it up...
...Ships must give 48 hours' notice of arrival...
...Already there has been an accident in which a tiny amount of LNG, just a cupful, spilled on a tanker deck during unloading and caused a crack several feet long...
...The Flameless Boom: What little public attention the hazards of LNG have received has stemmed from a 1970 Bureau of Mines study, run for the Coast Guard...
...Walter G. May at the Esso ,Research and Engineering Center in New Jersey...
...There are some complications, though...
...Last August, Distrigas official Gene Fetteroll put on a display of LNG safety which he capped by boldly plunging a burning cigarette into a dish of LNG...
...If some LNG escaped from a tank and touched the hull, it could crack...
...So let's study them...
...When the hull fractures, the effect on the gas tanks depends on how much strain is involved...
...Thanks to technical advances since the Cleveland disaster, new plants are generally considered safe-or at least as safe as any plant dealing with other flammable materials...
...This is 10 times as large as any loan the bank has made before, and there have been hints that the Treasury Department, in an unprecedented move, is considering setting up a special bank at the taxpayers' expense to finance just this deal...
...It would be better to let it burn itself out, otherwise the gas would just continue floating around on the water, go downwind, and cause worse hell somewhere else...
...Space age metallurgy was a long way off...
...Such a fire could begin if nearby vessels ignited the cloud, as happened during a recent naphtha spill near Staten Island...
...Since all LNG ships now in operation are foreign-flag vessels, this sometimes poses a problem...
...But both of these agreements pale when compared to the biggest deal of them all-a contract worth a reported $45 billion now being worked out between Russia and a triumvirate of U. S. companies...
...The Coast Guard, for example, can lecture ship captains when their gas gauges don't work, but they say there's not a lot they can do about broader issues of safety...
...Then it's gonna crack...
...Tank walls are designed to withstand the cold, but ship hulls are not...
...we took a launch out to meet her...
...The May study, concludes that a spill in harbor waters would be an "unacceptable development," in the words of a Distrigas executive...
...The advanced, almost magic, cryogenic technology made it possible to freeze natural gas in plentiful summer months, and store it for peak winter demand in a liquefied form (LNG), neatly compressed into a package one six-hundredth the size of the gas in its gaseous state...
...In a large spill, it spreads out to beat hell...
...One aspect to consider is the tremendous cost of the LNG plans...
...With any sizable tanker, the LNG liquid would continue to spill even if aflame, and could surround the ship and cover the channel...
...It was ignited, possibly by a cigarette, and burning LNG poured into the streets and sewers...
...Massive gas leaks would come from collisions, and as Dr...
...The protests failed and the tanks are going up, but the citizens have the consolation of at least one droll memory...
...But, says Marine Inspection Officer Harold Brackett, "We just don't know if they run them at all...
...They didn't have a repair manual for it, didn't know how to fix it, and couldn't have cared less...
...Distrigas has also contracted for Algerian gas-3 1 shipments a year by 1976-and has built facilities in Boston and Staten Island...
...The question then is, what else will be ignited: if the ship were 500 yards from shore, might it touch off oil and chemical storage tanks there...
...To keep morale up for this campaign, the gas industry has hit on a single theme-Clean Natural Gas...
...The films I have seen of spills-one small spill, the cloud reached a flame, the flame started back to the source in a whoosh," according to G. H. Martin of Boston's Distrigas Company...
...Yeah," Blomberg cracked, "they know English until a problem comes up, then they no longer speak it...
...The natural tendency most harbor firefighters have is to throw water on it...
...Amid the dozens of other complications the deals involve-in foreign relations, balance of payments, domestic gas rates, and the specter of bargains akin to the Russian grain deal-some basic questions about the safety of LNG shipments have been overlooked...
...He was furious: "You can't run a ship like this without expecting some minor problems...
...Any building or warehouse became a candidate for explosion as it filled with gas...
...Most felt it was the result of "superheating"-when the cold LNG hit the warmer water, it evaporated violently and set up a pressure wave...
...Gas companies, pipeline firms, shipyards, and others queuing up for this new form of liquid gold are investing some $1 million to study the hazards -but only after the LNG boom is already under way...
...The cloud would be flammable, and it would probably hang around long enough to ignite...
...Like everything else, we seem to end up frying in our own juices...
...No one was sure what had happened...
...The Federal Power Commission's recent decision to approve the deal between El Paso Natural Gas and Algerian suppliers was a one-shot ruling, concentrating on the specifics of the case rather than on overall energy-planning for the future...
...The worry now is about what happens when you start importing the stuff, not in 10-foot-thick, reinforced-concrete storage tanks, but in thin-walled ships...
...From the point of ignition, fire rushes back to the main source of fuel...
...And a hungry maritime industry is one of the strongest lobbies for the LNG imports...
...Columbia is still building the facility on the coast...
...Then, with the slightest spark, the cloud could create a holocaust equivalent to the burning of 100 Hindenburgs...
...Both industry and government have run studies on the plume spread, though neither study has been released...
...May explains what happened : The cold methane vapor...
...This could mean a large tongue of flame, moving through the city back to the tanker...
...Deals involving billions of dollars and billions of cubic feet of gas are now being negotiated with Algeria, Russia, and other gas-rich nations...
...The researchers went to the Gulf of Mexico and dumped 2,500 gallons of LNG...
...For a large-scale release of gas, both the ship's double hull and aluminum-on-plywood gas tanks would have to rupture-but this has happened often in oil tanker collisions...
...Though German experimenters have set off open-air gas explosions using small TNT blasts, Dr...
...Fourteen of the tankers are now in service, and 40 to 50 more are on order...
...But it's necessary to try to understand what might happen following a harbor accident involving LNG...
...Officials say such options as coal gasification, solar energy, or gas from organic wastes, are a long way off, and the LNG is needed as immediate supplement-but it is left up to the industry to fund and set up a timetable for development of alternative energy sources...
...Once any part of the plume started to burn, a "flashback" sequence would probably follow...
...The free and unconfined gas would be hard to detonate...
...David Burgess of the U. S. Bureau of Mines speculates that if LNG vapor seeped into a building and was touched off by a furnace or cigarette, it could blow up the building and in turn detonate the whole plume...
...Getting the foreign gas involves risky and high-priced arrangements in the Middle East, Africa, and Latin America-often requiring 25-year contracts, expensive liquefaction plants to freeze the gas for shipment, giant ships (costing two to four times as much as oil tankers) to carry it, and storage and regasification plants in the delivery cities where the gas is to be used...
...Hull Cracking: It would be bad enough if, as is usually supposed, only one of a ship's four or five tanks split...
...The oil-slick problem of a damaged tanker, which we are familiar with, polluting the beaches and so forth, would not be a problem with gas ships," said the president of General Dynamics last June, while testifying before a House merchant marine committee hearing on his company's plans for $90 million LNG tankers...
...Boston Harbor To see what our government is doing to protect against LNG hazards, I went to Boston harbor recently, to the office of the Captain of the Port...
...Anyone who has ever sprayed an aerosol can at a flame has a rough idea of how this works...
...On Staten Island, homeowner groups with names like Citizens' Committee Against a Fiery Death have exhausted themselves protesting Distrigas' construction of two enormous tanks in the area...
...In this gas-solves-all-ills view of the situation, a "spill" involving an LNG tanker would quickly clean itself up...
...All along the line, officials shuffle their feet when asked this question and point at the man down the hall...
...Jeezus...
...No one is really quite sure how to fight one of these fires...
...Worse, the gas hovering over a wide area might not just burn, but may actually explode...
...Blomberg said...
...so we put our money on the line, signed up contracts, and built terminals...
...Our regs say they have to take readings every 30 minutes in U. S. waters...
...This cold gas would sit in a layer along the top of the water and could drift into cities, ships, or whatever else was in the vicinity...
...There were troublesome unknowns...
...To burn, LNG, which is 95 per cent methane, has to mix with about seven parts oxygen...
...As evidenced by the repeated oil spills, ships do collide (140 tanker collisions and "hard groundings" were reported to the Coast Guard in fiscal 197 1 alone...
...The gas companies apparently feel no such stimulus...
...Flaming liquid would pour over the entire area near the crash, immolating nearby ships...
...When it was all over, 133 people were dead, 300 injured...
...While climbing on the natural gas bandwagon, preferring it to dirty fossil fuels, they seem to be unconcerned about where the "wonder-fuel" comes from...
...After a sequence of uneventful trials, researchers found that three seconds after they spilled a little LNG into an aquarium filled with water, a flameless explosion took place, blowing up the entire aquarium...
...it's not our responsibility...
...Still, there are recorded instances where seven per cent of the gas exploded, producing a leveling blast...
...LPG and LNG vessels may dock only during daylight, in good weather...
...At the same time, we said, people are raising serious questions...
...For a last incredible touch, environmentalists urged that some 600 acres intended as a "blast buffer zone" around the tanks be opened as a public park...
...The French tanker Descartes got all the way into the harbor on its second voyage and was unloading when it was noticed she had cracks in her tank membranes...
...and thermocouples which register changes in temperature and therefore might detect leaks of the cold LNG...
...But the quirks of LNG might well open up the ship's whole hull and spill all the gas...
...May said, given an eight-knot wind, predictions of' an eight to 12-mile plume are roughly correct...
...The ships are escorted by tugs, so that if a fire starts, the tugs can pull the ships out into the middle of the harbor...
...There are now about 50 plants around the country...
...Shipments like those into Boston will become more and more frequent in the coming years if many of the pending LNG deals go through...
...You wouldn't get a plume all the way across Staten Island before it caught fire...
...Not enough of the gas tank was left to determine the exact cause of failure, but experts pointed to poor design, use of marginally flexible metal, poor insulation, and inadequate inspection...
...By allowing expensive LNG, the Federal Power Commission has virtually decontrolled gas prices...
...If the gas caught fire, it would generate tremendous heat-enough to vaporize and burn the rest of the liquid gas...
...But you would have 788,000 barrels of liquid LNG in the tanker to worry about...
...The LNG's not going anywhere...
...Cleveland put the same damper on the LNG industry as the Hindenburg put on Zeppelins...
...On the way out, Coast Guard Lieutenant David Blomberg outlined the procedure for an incoming gas tanker...
...wartime shortages meant that corners had to be cut, so the equipment was made of a second-choice metal...
...The oil and gas companies provide the only figures on the size of reserves and have never fully admitted what exploration costs for new wells are...
...Drawing on the report, Rep...
...Larry Everman, also of the Coast Guard's Boston port safety office, remarked that he had been given no specific training in fighting an LNG fire...
...To guard against the risk altogether would require the use of costly low-temperature hull metals...
...They concluded that the explosion could assume damaging proportions in an actual gas spill...
...The liquefied gas would simply evaporate and disappear, turning into a fluffy white cloud that would float out of sight...
...The $1.7-billion deal will run for 25 years and is predicted to provide as much as 10 to 15 per cent of the total East Coast gas supply by the 1980s...
...The problem is the extreme temperature required to transport LNG...
...The results of the test were a surprise to everyone...
...Doom in a Plume For a spill from just one of a ship's five 25,000-cubic-meter tanks, Dr...
...During a recent dispute over placement of gas terminals on the East Coast, Schwing made five of his staffers available to local authorities...
...This includes two types of early-warning systems: gas detectors placed in the insulation on each gas tank and elsewhere around the ship...
...Since domestic gas reserves are, if not depleted, at least running low, eyes have turned toward foreign sources...
...Furthermore, the imports are driving up the cost of domestic gas, raising the value of U. S. reserves...
...If you get a spill in a tanker collision and the stuff comes gushing out, you can visualize a fair amount of it sloshing around the side of the ship," says Esso's Dr...
...After discovering that Columbia Gas System wanted to build an LNG terminal at a scenic spot which the state intended to buy for park land, the environmental groups urged that the tanks be moved to an industrialized, populated region instead...
...By 1980, a world fleet of up to a hundred tankers will be ferrying the gas from points around the globe to the U. S., with smaller shipments to Japan...
...How far the plume of gas would spread depends, among other things, on the rate of leakage, local breezes, trees and buildings deflecting its flow-and how soon it reaches a source of ignition...
...Nice Place for a Picnic At another citizens' protest against LNG ports, in Cove Point, Maryland, environmental groups made what can most kindly be called a bizarre intrusion...
...On October 20, 1944, one of the four storage tanks suddenly ruptured, spewing forth 1.2 million gallons of LNG (equivalent to about 100 million cubic feet of gas...
...LNG is considered an 'acceptable' risk," says Captain Schwing, "The placement of the terminals is in the hands of the local people...
...May says, "The chances of having a collision without having a fire are pretty damn rem0 te...
...Acceptable Risks When we boarded the Havis, we learned that the crew, rather than an international certification team, had set the relief valves...
...Even if the fire started with only one leaking tank, it would almost certainly generate enough heat to break other tanks as well...
...combustible gas vapor and engulfed several square miles of San Francisco in a sea of flames...
...Burning the Ship-Some experts feel the danger of a long, explosive plume drifting over a town has been overstated, mainly because the gas is likely to burn before it ever reaches town...
...Environmentalists have largely missed seeing the hazards of LNG...
...Yet when turned on, the gas alarm buzzer blurped, red lights shone, and the reader indicated the control room where we were standing contained the lower flammable level of gas...
...Some 30 projects are now being discussed or developed around ;the world, and new agreements are announced almost weekly...
...The last two LPG ships in here were shitboxes...
...Part of the Coast Guard's job is to check the ship's safety equipment...
...The transfer operation crew must be able to speak English...
...The nation's first commercial LNG plant had been operating successfully there for over three years, filling increased demands for natural gas from the city's wartime industries...
...Five: The likely chain of events here is fairly easy to imagine...
...It was disconnected...
...When the boats get to America, they will be unloaded at LNG facilities now planned for Boston, New York, Providence, Savannah, Los Angeles, and Cove Point, Maryland...
...But this is not the last item on the danger list...
...But in other tests at the Argonne Laboratory, the same type of explosion has definitely been caused by injecting LNG underwater-which might happen in a really massive dump which sent LNG cascading below the waves...
...The resulting fire flashed back to the ruptured naphtha ship...
...It hadn't been properly set, and they were getting a continuous alarm on it, and had just shut it off entirely...
...Government agencies have also been reluctant to face the basic policy question: Should we allow any LNG imports...
...I The prospects for seriously stopping the LNG momentum long enough to take a look at it, seem dim...
...The captain assured us there was no problem, however, signed the standard form, and said the gas detector system had been checked "continuously...
...The bigger the spill, the bigger the spreading...
...All we could hope to do was terrorize these people into considering the dangers of ship collision," he said...
...Two basic scenarios might follow a gas release: an immediate fire, caused by a spark from the collision, or the creation of a flammable vapor cloud...
...Burgess adds, if it's any consolation, less than IO per cent of the gas would be detonable, much would be too methane-rich or already dissipated...
...On the morning of my visit, the Havis, a 15,000-cubic meter Norwegian propane tanker (whose structure is basically like an LNG tanker) was due at 7 a.m...
...The publicly-funded Export-Import Bank is providing credits for the construction of the liquefaction plants and pipelines in Algeria and would be asked to help finance the Russian construction with a loan of $10 billion...
...In any major collision, grounding, or spill, there would be a whole range of hazards, the exact sequence of which is hard to predict...
...One didn't even have the gas detector system turned on...
...Not only does gas burn clean, it spills clean...
...Scientists working for Shell Pipeline claim that the explosions will take place only under special circumstances when the methane content is low, and in recent tests, the Bureau of Mines has not been able to get the LNG to blow up...
...Nearly all have gone ahead with the orders and construction plans first and scratched their heads about safety afterwards...
...Captain Robert G. Schwing, chief of the Coast Guard's hazardous materials division, explained: "I would just get all the people evacuated from the area first, throw some water on the surrounding buildings, and let the .gas burn...
...A tanker which ruptured in, say, New York harbor might well flood Manhattan with flames...
...But by 1958 the industry was back at it again, and in the mid-sixties it began a program to build LNG storage and freezing plants...
...Had, for example, one of the two Standard Oil tankers which collided in San Francisco Bay in 1970 been a 900-foot LNG tanker, the impact might have released a cloud of] Timothy Ingram is a contributing editor of The Washington Monthly...
...wants to spread out sideways just like pancake batter on a hot griddle...
...Within its limited authority, however, the Coast Guard has done what it could...
...Maybe it was an unlawful use of government monies to do it, but I thought we had a moral authority...
...Flames reached half a mile into the sky...
...Too much pressure inserted around the tanks could crack them, and there was no way of knowing whether the crew had set true pressure readings...
...10 industrial plants, 80 houses, and 200 automobiles were seriously damaged, and the city sewer system over an area of more than 30 acres was destroyed...
...The government study, conducted by the Bureau of Mines last year in Pittsburgh, reportedly came up with about the same findings as a team directed by Dr...
...Lighting Up Cleveland But sitting in the back of everyone's mind is what happened in Cleveland in 1944...
...There, a passing tugboat took on some of the vapor, which exploded in the tug's confined cabin space...
...If you have a fire, that's it," May says...
...The government is picking up the tab for a 25 percent subsidy on every $90-million LNG supertanker built in U. S. yards...
...In the end, the hardest question to answer is who should be responsible for heading off the holocaust...
...The largest U. S. deal approved so far is for the importation of Algerian LNG by the El Paso Natural Gas Company, the nation's largest gas pipeline company...
...Boston is the only U. S. harbor experienced in handling liquefied gases, with Boston Gas Company, Exxon, and Distrigas receiving regular shipments...
...The odds on hull cracking are hard to predict...
...The three firmsTenneco, Texas Eastern Transmission, and Lyndon Johnson's favorite contractor, Brown and Root-plan to spend $10 billion to build gas facilities which will later be transferred to Russian ownership...
...In a spill, the vapor's volume would be roughly 250 times greater than that of the liquid gas, and it would cover a considerable area: the contents of one large tanker could stretch a dozen or more miles...
...Just how big a threat this "violent vaporization" poses is not clear...
Vol. 4 • February 1973 • No. 12
