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Data obtained from the Mine Safety and Health Administration (MSHA) indicated a total of 889 underground (6.0%) and 13,982 surface (94.0%) mining operations.1

Aug 1, 2009

Industrial minerals enjoyed a fairly successful year in 1978, despite the sluggish economy, inflation, and environmental restrictions. A glance at US Bureau of Mines statistics shows that, in general, production of industrial minerals increased from + 1% (salt) to as much as 26% (sulfur, other than Frasch or recovered). A few industrial minerals showed a decline; fluorspar production, for example, registered a 23% decrease in 1978 from 1977 due to the closing of three domestic mines. Bromine, natural sodium sulfate, Frasch sulfur, and vermiculite also had production decreases of 2-6% in 1978.

Jan 5, 1979

The Candelaria deposit was first discovered by Spanish prospectors in 1863; but its silver ore was not exploited on a large scale until 1873, when the Northern Belle mine was opened. The first Northern Belle mill was built at Belleville, 13 km (8 miles) to the northwest. From 1876 to 1886 the Northern Belle paid over $1 million in dividends each year. In 1882 a 43 km (27 miles) pipeline was built to Candelaria from the White Mountains to the west to furnish water for the mills and town at Candelaria; it was 100 mm (4 in.) in diameter, hand- riveted, and made in England. Sections of this pipe are used. as claim posts today. At its terminus at Metallic City, above Candelaria, a large concrete reservoir was built and called Metallic Lake. It is being used today by Candelaria Partners. Production at Candelaria declined after the mid-1980s, revived for a short period in the early 1890s, and during the 1920s a 300 ton mill operated for three years. Candelaria Partners is owned jointly by Occidental Minerals and Congdon and Carey, with Occidental being the operator. An engineering study done in mid-1979 resulted in engineering for the plant commencing in late that year and heap leaching being started in September 1980. Two million tons of ore per year containing 108 g Ag and 0.28 g Au per mt (3.15 oz Ag and 0.008 oz Au per st) will be mined from the Lucky Hill and Mount Diablo .areas about 1.6 km (1 mile) up Pickhandle gulch from the heap leaching operation. Waste -to -ore ratio is about 2:l. Ore is mined by front-end loaders and hauled by 85 ton trucks to the primary crusher, a 1,070 by 1,780 mm (42 by 70 in. ) gyratory. Primary crushed ore is conveyed to a stockpile of 10,000 tons live capacity from which it is reclaimed by hydraulic reciprocating feeders and conveyed to the crushing and agglomeration facility. This unit is composed of a 1.8 m by 2.6. m (6 ft by 12 ft) double deck screen, a 2.1 m (7 ft) standard cone crusher, and three conveyors. At the conveyor transfer points NaOH and NaCN solution is sprayed on the ore as it falls through a row of 75 mm (3 in.) hanging steel bars. During this process of turning and dividing the ore, the fines agglomerate with the coarse ore to give better percolation for the leach solution on the heaps. Provision was made for the later addition of 2 kg per mt (4 lb per st) of cement to aid in the agglomeration. Agglomerated ore at minus 50 mm (2 in.) size is then conveyed to a 390 mt (430 st) loadout bin where it is transferred to 85 ton rear dump trucks for haulage to the leach pads.

Jan 1, 1981

A summary of the more important work by previous workers is followed by brief descriptions of the rock formations and regional structure. Type examples of the various forms of mineralization are described and the conclusion is drawn that there has been one main period of ore formation, namely, during the "Viti Revolution" in the mid or late Miocene.INTRODUCTIONThe Crown Colony of Fiji is comprised of a group of some 250 islands situated between latitude 160 sand 21 0 S and longitudes 1770 E and 1780 w: By far the greater, part of the total area, 7,083 sq. miles, is contained within the two main islands, Viti Levu 4,053 sq. miles, and Vanua Levu 2,128 sq. miles, and it is to these that most geologists have directed their studies. The most detailed work has been in the Tavua Basin, north coast of Viti Levu, centering about the mining town of Vatukoula and the geology of this area forms the subject of a separate paper by Blatchford (this volume p. 13).The present contribution summarizes geological knowledge of Fiji, at the time of writing (Feb. 1952), with particular reference to the known mineralIzation, but excluding the Tavua Basin. For general descriptions of Fiji's topography reference should be made to the recent works of Derrick and Dunkin.PREVIOUS WORKERSPeriod 1840-1930Prior to the gold rush of the early 1930s the visiting geologists concerned themselves in the main with the struc...

Jan 1, 1953

By H. Sevim

In a recently developed long term open pit production planning model, the optimum plan is found by exhaustively searching through nested pits of maximum-metal contents. A more efficient, dynamic programming (DP) based search algorithm now replaces the exhaustive search algorithm which was requiring prohibitively long execution time in real life cases. The logic and the formulation of the newly developed search algorithm are illustrated through a small hypothetical case. A real life gold deposit is treated to demonstrate that the algorithm does indeed find the optimum production plan among all possible plans. A comparison, in terms of computational savings between the two algorithms is also given.

Jan 1, 1994

By Terrence M. Carroll, Chu E. Ho, Dimitrios Niarchos

"Construction of the new extension to Terminal 4 at John F Kennedy International Airport in Queens, New York involved the application of tapered piles for foundation support. Initial design based on past load testing experience had indicated that a pile depth of 65 feet was necessary to achieve a capacity of 394 tons. However, piles with a single length of 62 feet were ordered and installed, which led to marginal performance of the piles. This paper presents the technical considerations for mitigating the situation based on a systematic review of three preliminary pile load tests and dynamic capacity measurements on the shorter piles. Consideration was given to the long term gain in capacity of tapered piles due to set up in the Glacial Sand. The observational approach to the evaluation of piling performance adopted on this project resulted in salvaging many piles which failed to comply with the specified driving criteria. It was acknowledged that a more prudent course of action was for the Contractor to have ordered more appropriate pile lengths that allowed for potential variation in soil conditions across the site. The 4.6% saving in pile material did not warrant the effort that was required to mitigate the 39% of installed piles that did not meet the specified driving criterion.INTRODUCTIONAn expansion project at John F. Kennedy International Airport in Queens, New York involved the Phase 2 extension of Concourse B at Terminal 4. The site consists of 4 to 5 feet of pavement over about 10 feet of hydraulically placed sandy fill. Below this is a layer of marsh deposit, comprising of soft organic clay and peat, up to about 11 feet thick. Beneath the marsh deposits is a deep layer of glacial sand which extends to well over 100 feet below ground. Figure 1 shows the typical subsurface profile at the site. The new structures were supported on 223 steel tapered piles. The piles consisted of a straight steel pipe 18 inches in diameter and 0.375 inches thick, with a 25 feet long tapered bottom section (diameter varying from 18 inches down to 8 inches at the pile toe). The piles were first driven to the founding depth and subsequently in-filled with concrete. The concrete strength (fc) specified was 4,500 psi and the yield strength of the steel piles (fy) was 50 ksi. Initial pile design, based on earlier experience with static pile load testing for Phase 1 development at the same terminal, indicated that a pile length of 65 feet was necessary. However, piles with a single length of 62 feet were ordered and installed by the Contractor, leading to marginal performance of the piles. This paper presents the technical considerations for the adoption of alternative pile driving criteria, based on a systematic review of the preliminary static load test results for the present site and PDA measurements obtained during pile installation, in order to accommodate the capacity of the shorter piles."

Jan 1, 2017

By M. D. Carver

This publication describes development by the Bureau of Mines of a quality evaluation procedure for certifying the adequacy of production lots of Kroll process zirconium sponge the Bureau had produced for reactor applications. After the procedure was devised, the next step was to apply it in controlling the quality of one-half million pounds of zirconium sponge com-prising 259 production lots, called blends, originating at the Metallurgy Research Center of the Bureau at Albany, Oreg. The Bureau concluded that the evaluation method developed was adequate and that by this method the zirconium blends having impurity levels or other property values outside specification limits were differentiated and thus were diverted from nuclear energy end uses. The research was performed under contract for the Bureau of Ships, Department of the Navy, and for the Atomic Energy Commission (AEC).

Jan 1, 1960

By James Bowron

CONSIDERING the importance of the steel trade and the strategic position occupied in it by the Birmingham District, it may be surprising to many to realize that even the first pig iron smelted with coke was made in Alabama on Feb. 28, 1876, although merchant pig iron had been produced in Rockwood, Tenn., in 1867, a plant which is still in active operation. The heavy deposit of Clinton ore extending from Pennsylvania into Alabama, varying greatly in accessibility on account of geological changes such as erosion or anticlinal upthrow, varies equally as much in thickness and in quality. The brown ores extensively scattered through the South also vary materially in quality, some being relatively low in phosphorus and high in manganese, and vice versa. The red ore varies materially in phosphorus, but the iron produced from these ores was always considered to be too high in phosphorus for treatment by acid Bessemer or open hearth and did not contain sufficient for the basic Bessemer process. Under these conditions there remained only the basic open hearth as a possibility, and for many years it appeared impossible to use it, because, with coke smelted iron, the silicon was too high to permit its use in basic lined furnaces.

Jan 1, 1924

The treatment of beach sands in'' the Bunbury/Capel' area for the extraction of ilmenite is a very recent development in the mining industry in'J7estern Australia. Nevertheless since the commencement of production in 1956, ilmenite has become the sixth most important mineral produced. The increasing world recognition of W.A. as a major' Iiroducer of ilmenite is due primarily ' to its low chromic oxide. ; (Cr203 content,, 0,03% to 0.04%, combined with a medium to high grade TiO2 content, 54% - 6 , supported by large reserves, a'. stable government with close access to good shipping facilities.. Ilmenite is produced from-these deposits at low-costs, enabling the industry to compete on world markets despite high rates for sea freights because of the distance from.major markets.

Jan 1, 1964

By M. D. Strachan

Technical & Procurement Services Limited (TECHPRO) in Ashford, Kent, UK, have been appointed as Project Managers for the major rehabilitation of the Copper Smelting complex of Nkana Division, Zambia Consolidated Copper Mines Limited, (ZCCM) Zambia. In outline, the overall scope covers three main areas: a) Transfer and implementation of new technology into Zambia for the production of primary copper. b) Replacement of gas collection and gas treatment circuits to guarantee high quality feed to the acid plants. c) Completion of a number of minor projects in the copper smelter and associated utility plants to complement changes in the primary smelting technique. This paper describes the Project Management methodology and style used by TECHPRO to tackle typical problems that arise in retrofit projects of this type. Reference is made specific aspects of the smelter projects to illustrate solutions to the problems. The subjects. addressed highlight the complexities not only of having a -Client 5,000 miles from the Project Office, but also the difficulty of co-ordinating and controlling the performance of min sub-contractors who are also geographically distant.

Jan 1, 1991

By Rossier W. Raymond

John Birkinbine was born Nov. 16, 1844, at Reading, Pa., the eldest son of H. P. M. Birkinbine, widely known as a hydraulic engineer. The family removed subsequently to Philadelphia, where, as a young man he established with his father the office now, continued by his sons, after more than 60 years. His education was received at public schools, the Friends' High School in Philadelphia, the Hill School at Pottstown, Pa., and the Polytechnic College of Pennsylvania, where his studies were interrupted in 1863-4 by service in the Union Army, which included participation in the battles at and around Gettysburg. Later, he devoted two years to work in a machine shop; and subsequently he became associated with the late P. L. Weimer, under the firm name of Weimer & Birkinbine, operating the Weimer Machine Works at Lebanon, Pa. Much of his work was in mining, metallurgy, and blast-furnace construction. As manager for the South Mountain Mining & Iron Co. he carried on experiments with various fuels for iron-ore smelting while maintaining the furnace in constant operation. The carefully recorded results obtained were widely published, and are referred to in text-books by other metallurgists as most complete. From his Philidelphia office he was sent to nearly every State, and to Canada and Mexico, for examinations, reports, constructions or im-provements in iron-ore mines, blast furnaces, iron works, water supplies, hydraulic development, irrigation projects, etc., and his engineering knowledge was requisitioned by several Eukopean corporations. A number of business trips were made to Mexico, beginning with a visit to the Cerro de Mercado at Durango,,before railroads were established in that. portion of Mexico, to make a critical examination and report on this "Iron Mountain." Later visits covered other localities and engineering problems, familiarizing him with the major part of the iron industry in Mexico. The late disturbed political conditions in that Republic have retarded the probable enlargement, modernization, and improvement of much of the iron and steel industry of Mexico, upon which he investigated and . reported for various capitalists on both continents. One interesting subject included in these reports was a proposed electric furnace, to be operated by energy from water power.

Jan 1, 1916

By A N. Kusnanto, D Sims, L Henim, S Crispin, J Hertrijana

The high sulfidation Purnama Au-Ag deposit located on the Indonesian island of Sumatra entered production in mid-2012 following a two-year program of construction and development. Discovered in 1997 following a regional stream sediment geochemical sampling program by the Normandy Anglo Asia joint venture, it is the first and largest deposit in G-Resource’s Martabe Project to enter production and is the centrepiece of a series of six deposits totalling 8.1 Moz Au and 73.8 Moz Ag in Mineral Resources (G-Resources, 2013a).In 2011 investigation into the controls of high-grade mineralisation in isolated parts of the deposit identified a potentially significant mineralisation style which had not been previously recognised or accommodated in the resource model. An extensive investigation of core and logging data followed to confirm the distribution of the somewhat unusual mineralisation style – a sedimentary-like cavity infill of very high-grade auriferous pyrite within the steep hydrothermal breccia feeders to the system. With the bulk of mineralisation located within the adjacent volcanic sequence and sandy-matrix phreatomagmatic breccia surrounding the feeders, the lack of constraint for high-grade intersections in the hydrothermal breccia zones had potential to significantly impact the mine plan in the lower sections of the planned pit through overestimation of local gold grade. Combined with new data emerging from grade control drilling and infill resource drilling in the pit, a program of reinterpretation of the deposit was initiated to update the geological and alteration framework underpinning the resource model. The result has improved the economics of the project and added metal to the Ore Reserve for Purnama.CITATION:Sims, D, Henim, L, Hertrijana, J, Kusnanto, A N and Crispin, S, 2014. Remodelling the Purnama deposit – an interpretation case study from G-Resources Martabe Project, Indonesia, in Proceedings Ninth International Mining Geology Conference 2014 , pp 229–236 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By E. S. Bumps

A series of macrographs are presented for the purpose of graphically recording the strain phenomenon that accompanies the energy transition in the Charpy impact testing of a mild steel that is susceptible to strain aging. STRAIN patterns in mild steel Charpy impact specimens were obtained in order to determine whether, on the first appearance of plastic strain during deformation, the initial fracture cracks appear in the region of plastic strain or in the elasti-cally deformed regions between. Although this attempt to locate the initiation of cleavage was not successful, the observed strain patterns illustrating various stress conditions in partially deformed Charpy specimens are presented along with a discussion of the possible dependence of transition energy on the yield phenomenon. Earlier work on the development of strain patterns in mild steel have been reported by Fry1 and later by Jevon.2 Harris, Rinebolt, and Raring3 observed characteristic strain markings on the surface of Charpy V-notch impact specimens fractured above and below the transition temperature which they presented schematically. It is intended that the strain figures presented here will add to the literature a graphic correlation of strain with transition energy in impact specimens. Samples of % in. round hot rolled, 0.20 pct C steel were machined to standard 0.394 in. sq, V-notch Charpy impact specimens. Preliminary testing involved determination of transition temperature, Fig. 1, using a Sontagg impact tester. These data were subsequently used to select temperatures above, within, and below the transition range at which specimens were partially deformed. Partial deformation was obtained by either varying the energy or the testing temperature, see Table I. Macroscopic strain figures shown in Figs. 2 to 19 were produced by several metallographic repolish-ing and etching steps. The macroetchant used was as follows:4 120 g HCl, concentrated; 100 ml water; and 90 g cupric chloride. Strain figures were obtained on the outer surface and on sections through the central portion of the impact specimens in order to determine an approximation of the volumetric strain pattern. In the tensile strain figures reported by Jevon, it was found that strain etching would not work immediately following strain unless the material was heated to 200°C. The impact strain patterns presented here were obtained without this heating, but the specimens were not etched until ten months after straining. This confirms a discussion of Jevon's paper, in which it was pointed out that strain figures can also be developed after aging for long periods of time at room temperature. Hardness of the strained and unstrained portions, revealed by the etched pattern, was explored using R, impressions converted to R, hardness values. Discussion of Results In the impact test, as in the tensile test, some parts of the specimen yield and deform plastically, while other regions are deformed only elastically. The plastic deformation bears a relation to the imposed stress pattern. In the strain figures presented here, the plastically deformed regions are the dark etching ones. The strain figures are always symmetrical because the stress state in the Charpy-type specimen under impact loading is symmetrical. The difficulties encountered to produce initial cracks are intimated in Figs. 2 and 4. At a temperature of —75ºF, the stress was not sufficient to pro-

Jan 1, 1953

By Henning E. Soderberg

Yesterday, air pollution was somebody else's problem -- today, it is everybody's problem. The coal industry with thermal coal drying, is aware of their problem and the necessity of doing an acceptable job; however, there is much to be said as to how good a job is required and what performance limits should be set up. American Air Filter Company has been one of the pioneers in the solution of the thermal coal dryer dust problems, Because of high moisture content, products of combustion and occasional temperature surges, only wet collection has been considered as the practical approach. Our first installation goes back some 12 years with a total to date of 29 Individual wet collectors, each, fabricated of suitable corrosion-resistant material, at 14 operating plants. To eliminate a potential air pollution problem, a performance requirement of not more than approximately one-quarter (1/4) grains per cubic foot in the dust collector discharge was used. In nearly all installations, operating performance surpassed requirements, but discharge stacks were not entirely free of discoloration. However, plant nuisance and air pollution complaints were eliminated. This satisfactory performance was accomplished by medium priced wet dust collectors operating at a 4-6" W.G. pressure drop with cater drain requirements of about 1 gallon of drain water per 1000 cubic feet of air exhausted.

Jan 1, 1962

By John C. Machisak

INJURY DATA and experience at coal mines in the United States for 1957 are presented in this bulletin under the following general sections: (A) General injury experience: Tables 1-6: Current data on number of fatal and nonfatal injuries, frequency and severity rates, and average severity. (B) Selected injury experience: Tables 7-36: Current data on causes of injuries, distribution of injuries by part of body injured, days of disability, extent of hand and machine loading, experience by employ¬ment and production groups, and various other operating factors and physical conditions related to the occurrence of injuries at the Nation's coal mines. (C) Injury experience, by States: Tables 37-41: Data on injuries, injury rates, employment, causes of injuries, and severity rates. (D) Major disasters: Table 42: Data on major disasters from 1948 to 1957. A major disaster is defined as a single accident in which, or as a result of which, five persons or more are killed instantly or die at any time thereafter. (E) Historical coal-mine-fatality experience: Tables 43-47: Data on fatalities and their causes at bituminous-coal, lignite, and anthracite mines from the earliest records through 1957.

Jan 1, 1960

By J. Kretschmann, N. M. Smith, J. F. Brune, P. Goerke-Mallet

Coal production and coal use for electric power generation are diminishing worldwide. Germany will phase out lignite mining as well as lignite and hard coal-powered electricity generation by 2038. In the United States, coal production has dropped by more than 50% since 2006, including in key coal production states like West Virginia and Wyoming (EIA 2021). Closing mines and power plants across entire mining regions has significant socio-economic impacts. Existing industries must be focused on the post-mining economy by attracting new industries, and implementing job retraining programs for displaced workers, as former mining regions transition towards agricultural, industrial and recreational use. This paper examines the German “exit from coal” under the 17 UN Sustainability Goals and illustrates the complex procedures, interrelationships, risks, and rewards of the transition towards renewable energy sources, including wind, solar, hydrogen, and bioresources.

Mar 2, 2022

By William Gleason

From Nov. 16-20, the Extraction 2025 Conference will be presented in Phoenix, AZ. The unique conference brings together the 12th International Copper Conference, the 6th International Symposium on Nickel and Cobalt as well as cross-cutting symposia. Extraction 2025 is co-organized by The Metallurgy and Materials Society (MetSoc) of the Canadian Institute of Mining, Metallurgy and Petroleum (CIM), the Society for Mining, Metallurgy & Exploration (SME) and The Minerals, Metals & Materials Society (TMS). The previous, and first Extraction meeting (Extraction 2018) was held jointly by these three societies seven years ago in Ottawa and was a huge success with more than 90 percent of respondents indicating interest in attending a future event. Kimberly Mills, senior process engineer at Samuel Engineering, is the lead for SME. “This installment of Extraction is featuring Copper 2025, Nickel-Cobalt 2025 as well as crosscutting symposia,” said Mills. “All three societies participate on the International Organizing Committee for the Copper Conference Series and are well situated to host this event together. TMS is also hosting the Ni-Co conference this year and agreed to include it as part of Extraction. There are many aspects that can be shared between these commodities to share information on processing technologies and to learn from each other.” SME is the overall conference chair and running the logistical aspects of the event, which includes managing all aspects of the venue and the registration system as well as tours and short courses, Mills said. “SME has many dedicated members serving in various capacities on organizing and programming committees, including Nick Gow serving as Technical Committee Co-Chair for Copper and Adam House assisting on the Copper IOC.” When Extraction 2025 kicks off, it will be focused on the metals needed for the global energy transition with a special focus on copper and nickel-cobalt. “With as rapidly as the industry is changing and the huge demands for these metals we have some serious challenges ahead of us,” Mills explained. “These challenges require collaboration, creative solutions and engaging experts, both inside and outside of our fields, with a push for sustainable sourcing, ethical supply chains, environmental and social responsibility.” The International Copper Conference was started in 1987 as a collaboration between the Institute of Mining Engineers of Chile (IIMCH) and MetSoc of the CIM. The event is typically held every four years and has always been held as a standalone or headlining event at a society annual meeting, said Mills. “Over the years, this conference series alone has brought together members of IIMCH, MetSoc, TMS, SME, the Society for Metallurgists and Miners from Germany (GDMB), the Mining and Materials Processing Institute of Japan (MMIJ), the South African Institute of Mining and Metallurgy (SAIMM) and the Nonferrous Metals Society of China (NFSOC),” she added. “Being a part of Extraction allows for even more sharing of ideas and expansion of networking. This conference has not been held in the United

Oct 1, 2025

By M Hopkins, A Mutale, A E. Vidal da Silva

The Cliffs Nickel Mine extracts a narrow near vertical nickel vein using a mining method of underhand bench stoping with paste backfill. In 2014, at a depth of 400 m below surface, the Northern block of the mine began to experience squeezing within ore development. At first the deformation was localised, within 30 m of the stoping front, but later became pervasive extending across the Northern block and resulting in a hiatus in mine production. The global mechanism is a progressive pillar failure, where the inter-level pillars in advance of the production front could no longer withstand the induced load and progressively yielded. The local mechanism of failure was observed as crushing of the massive sulphide ore and ‘punching’ of the pillars into the ultramafic hangingwall exhibited as floor and sidewall dilation and unravelling of the mafic footwall. The cause of the global mechanism was attributed to a combination of factors, including: high overall extraction ratio, small vertical pillar heights between ore development, high stress in relation to the low rock mass strength, shallow stope front angle, and insufficient ground support capacity. Following the progressive failure, the remnant rock mass conditions across the northern block were severely degraded, with numerous falls of ground that led to a reassessment of the mine plan. Recovery of the Northern block started in 2016 as a staged process. Development of the safe recovery work methodology involved a number of considerations, such as: production sequencing, development access design, ground support, and development of specific procedural controls. The Northern block was then broken into smaller mining precincts based on tactical factors such as location, ease of access, scale of rock mass damage and nickel content. A specific ground support standard and work methodology are employed, while cycle sheets are used to ensure quality and completeness of work. Large intersections showing signs of deformation have either been bypassed or treated using Rocprops to maintain stability during stope production. This approach has been successful in safely regaining access and restarting production in areas that had previously been removed from the mining reserve.

Mar 15, 2021

Professor N. S. Budavari holds a Dip!. Min. Eng. from the Technical University of Sopr on, Hungary, and a Ph.D. degree from the University of Newcastle-upon-Tyne, U.K. Mr J. J. Geldenhuys, Pr. Eng., is Divisional Manager Mining of Anglovaal Limited, being in charge of Prieska Copper Mines (Pty) Limited, Loraine Gold Mines, Limited, and Village Main Reef Gold Mining Company Limited.

Jan 1, 1983

By Richard Harrison, Frank Lim

"Lifting of slurry from the seabed mining machine to the surface production vessel is a critical element of any deepwater seabed mining system. A Vertical Transport System (VTS) comprises pump(s), riser string, connectors and hang-off assembly as its main components, but it is the pipe material, riser configuration and installation method that often attract the most discussions.This presentation will feature important VTS design work 2H has done over the years for different stakeholders, and highlight the work carried out as a partner to the EU funded Blue Mining Joint Industry Project.The key challenges faced by a deepwater VTS are:??High riser payload??Large deck space for storing riser joints??Long time to deploy and retrieve riser??Uncertain metocean conditions??Vortex induced vibrations??Weld and connector fatigueIncreasing the water depth further sees the longer and increasingly ‘springy’ riser experiencing axial resonance caused by wave induced vessel heave motions being close to the riser resonant period. This can lead to snatch loading and fatigue failure in the riser.The presentation will discuss the above design issues, analysis requirements and provide guidance on pump/riser selection. Solutions to mitigate the resonant response issues will also be proposed.."

Jan 1, 2017