Supply Boat Research Articles

Study of Sanitation Levels of Passenger Ships Boying at Tenau Port

Ship sanitation is one of the efforts at environmental risk factors on ships to break the chain of disease transmission in order to maintain and enhance health status .Poor ship sanitation will cause many problems in terms of physical, health, aesthetics and human survival The aim of this study is to know the description of the sanitation conditions on passenger ships that docked at the Kupang Tenau Port in 20 22. The type of this study is descriptive. Population in this study is all passenger ships that dock at the Port of Tenau Kupang from 4 to 17 March 2022 totaling 8 vessels. Accidental Sampling is a technuque for taking sample in this study (which is coincidenceany) totaling 8 ships. Instrument in this study used form of sanitation inspection from Health Office shipport. The results showing that on deck sanitation aspect there are 2 (25%) ships no fulfil condition on aspect cleanliness and good was neatly arranged and 6 (75%) ships fulfil terms. On aspect sanitationof crew member's room and passenger's room there are 5 (62.5%) not fulfil condition on aspect cleanliness and 3 (37.5%) ships fulfil terms. On aspect sanitation bathroom and tailet 8 (100%) boats no fulfil condition on aspect no smells fierce, 1 (12.5%) no fulfil condition on aspect good function and 8 (100%) ships fulfil condition on aspect cleanliness, not a place to store goods and there are no insects. On aspect sanitation kitchenof the 4 ships made inspection whole boat no fulfil condition on aspect wash equipment with hot water and 3 (75%) ships not have trash cover. On aspect sanitation room cooler thera are 4 (100%) vessels full conditions (100%). On aspect sanitation warehouse supply boat there are 1 (25%) ship no fulfil condition on aspect cleanliness and 3 (75%) ships fulfil terms. On aspect sanitation handler food there are 4 (100%) ships fulfil conditions (100%). On aspect sanitation clean water supply there are 8 (100%) vessels full conditions (100%). Conclusion from 8 (100%) ships ther

Propulsion Shaft and Gearbox Failure in Marine Vessels: A Duration Model Analysis

The need to mitigate downtime in marine vessels arising from propulsion system failures has led ship operating companies to devote enormous resources for research based solutions. This paper applied duration models to determine failure probabilities of shaft and gearbox systems in service boats. Using dockyard’s event history data on boat repairs and maintenance, we applied Kaplan Meier hazard and survival curves to analyse probability of failure of shaft and gearbox systems in supply, crew and tug boats. We found that average time to shaft and gearbox failure was 8.33, 5.23 and 5.21 months for tug, supply and crew boats respectively. The hazard plots however, showed that supply boats had higher probability of failure than crew boats and then tug boats in that order. Further analysis using Cox regression model showed that the boats’ shaft and gearbox system failures were significantly affected by level of lubrication oil, stress corrosion cracking and impacts on the propulsion system’s components. The paper proposes that design of maintenance schedules for service boats should take the following into consideration: 1) estimated survival limits or failure times of propulsion system’s shaft and gearboxes, 2) significant risk factors that affect failure mode of the propulsion system components.

Coiled Tubing Operations From a Work Boat

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 141234, ’Coiled Tubing Operations From a Work Boat,’ by N. Long, SPE, Brunei Shell Petroleum, and R. Raj, S. Srisa-ard, SPE, and N.H. Son, SPE, Schlumberger, originally prepared for the 2011 SPE/ICoTA Coiled Tubing and Well Intervention Conference and Exhibition, The Woodlands, Texas, 5-6 April. The paper has not been peer reviewed. Small offshore platforms have low deck-load capacity, and available deck space is insufficient for coiled-tubing (CT) workover operations. To find a solution to this issue, CT operations from a vessel were discussed and subsequently developed more than a decade ago. In 2002, the technique was refined substantially to improve safety and reliability, which allows well intervention from the deck of a floating anchored vessel. This technique uses a system that provides emergency CT disconnect and effectively compensates wave motion. Introduction As with any mature oil and gas fields, maintaining and improving oil and gas production is considered part of production operations. Each year, Brunei Shell Petroleum typically selects a minimum of more than 60 wells as candidates for CT intervention. These candidates usually are distributed over 30 different offshore platforms. In terms of operational time, this intervention objective normally requires continuous activity for 7 to 8 months. When studying the feasibility of conventional CT well intervention on a small production platform, there are normally three main issues to be examined. First, the platform deck area for placing equipment should be sufficiently large for placing CT equipment, pumping equipment, wireline equipment, and testing equipment, and for allowing equipment access spaces. Second, the platform crane must be able to lift equipment dynamically from a supply boat to the platform. Third, the production-platform structure must be strong enough to withstand the total weight of the CT equipment. In Brunei, normally it is not feasible to place all the CT equipment on offshore production platforms because the decks of those platforms are too small. CT-intervention-work targets on three-leg platforms and four-leg platforms that have available deck space range between 214 and 1,905 ft2. The maximum deck loads corresponding to these areas are in the range of 19 to 173 t. The installed crane on these platforms is primarily for lifting small loads, which are needed to support production operations. Therefore, the dynamic crane capacity is usually less than 5 t, and its boom length is approximately 15 ft. CT well-intervention work commonly includes wellbore cleanout, wellbore mechanical-obstruction retrieval, sand control, adding perforations, and matrix acidizing. To cover all these types of work, the deck-space requirement for setting up equipment should be at least 3,500 to 4,000 ft2 (or more) and deck-load capacity should be between 170 and 270 t.

Passenger submarine concept design for oil production offshore systems

The paper proposes an innovative solution to transport workers of offshore oil production platforms from the coast to their units, which operate at the Pre-Salt exploration, 300 km from the coast. A passenger submarine concept design was developed, justified by the range of practical obstacles observed in the current modes of transportation, helicopters and supply boats. Requirements like operational depth (100 m), passenger capacity (250 people), and cruising speed (minimum 13.4 knots) are defined, based on estimates. Firstly, it seeks the adoption of air-independent propulsion (AIP) systems, by fuel cells (PEMFC). However, the work progress leads to an entire electric propulsion system. The internal arrangement is elaborated, regarding passenger comfort, structural constraints, allocation of batteries and ballast tanks. Then, after a hydrodynamic hull optimization, by Computational Fluid Dynamics analysis, we provide a final configuration with 100-m length and 9.7-m diameter, operational speed of 16 kt, and autonomy of 26 hours.

Coiled-Tubing Operations in the Panna Field Offshore Western India

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 100149, "Operability Challenges During Coiled-Tubing (CT) Well Intervention: Panna Field Case Histories From Western India Offshore," by S. Kale, SPE, and R. Proctor, SPE, BJ Services Co., and S. Paliwal, SPE, and S. Nayak, SPE, BG E&P India Ltd., prepared for the 2006 SPE/ICoTA Coiled Tubing and Well Intervention Conference and Exhibition, The Woodlands, Texas, 4-5 April. Coiled tubing (CT) was used in well interventions offshore western India. Well completions are open hole, open hole with tail pipe, and cased hole with swell packers. CT entry was essential to operate sliding sleeves installed in the completions. The full-length paper documents case studies and reviews attempted solutions such as bottomhole-assembly (BHA) excitation tools and contact-friction reducers to extend reach and increase downhole force. Introduction Located off the west coast of India, the target reservoir in the Panna field is a limestone layer. Horizontal wells have been drilled and completed in the field since 1997. The main difference between the wells completed in the late 1990s and current wells is the horizontal-section length. Challenges associated with CT operations can be considered as logistical and technical. The main logistical challenges include limited crane capacity and deck space for CT rig up. Technical challenges include limited CT downhole force. Because of logistical challenges, the preferred CT size cannot be used on most platforms. Logistical Challenges Panna field has two types of platforms, one with nine slots and the other with 15 slots. The nine-slot platforms have limited deck space and crane capacity. Larger CT sizes such as 1 3/4-in.-outside-diameter (OD) pipe cannot be rigged up on nine- slot platforms but can be used on the 15-slot platforms. Two memory-production-logging (PL) campaigns were undertaken on the 15-slot platforms. Because of limited deck space on some platforms, fluid-pumping and nitrogen equipment, tanks, and mixing equipment were offloaded to a dedicated supply boat as required. This presented the logistical challenge of timing the operations to boat availability and tide conditions. Technical Challenges The two most important technical challenges faced by the team were CT-reach prediction and identification of possible solutions to meet well-intervention objectives. The objectives of well interventions in late-1990s completions were acid stimulation and memory PL. Current completions require sliding-sleeve manipulation, acid stimulation, and PL. Accurate CT-entry predictions require use of a CT simulator. In addition, the engineer using the simulator must have a thorough understanding of the modeling parameters and analysis process.

Dent 손상을 갖는 원통부재의 최종강도에 관한 연구(제2보) -굽힘 하중을 받는 경우-

Several types of steel structures which are employed in offshore petroleum activities are constructed with tubular members. These structures are usually subjected to various types of loads such as normal functional loads and environmental loads. Furthermore, accidental loads may also act on the leg or bracing members due to supply boat collisions and objects droppings from platform decks. The extent of damage caused by these loads ranges from total collapse of the structure to small damage which may not have serious consequence at the time of accident. To make optimal design decisions regarding structural safety and economical efficiency, it is very important to be able to assess the influence of damages on the performance of damaged structural members. In the End report, a series of calculations is performed to study the effects of different parameters on the load carrying capacity of such damaged members under pure bending. And the results of analysis are compared with experiment results.

Ocean Drilling Program investigates hydrate ridge

There are several ways to get onboard the JOIDES Resolution, a 143‐meter long converted oil tanker that is a floating laboratory, and the pride of the Ocean Drilling Program (ODP).You can meet up with it at a port of call, or set down on its helicopter pad. Or you can hitch a ride by overnight supply boat, and then get lifted by crane to the Resolution by clinging to the outside of a rope transfer basket as this reporter did.

Through-Tubing Well Seismic: A Mast Campaign Across an Offshore Producing Field, Saudi Arabia-Kuwait Partitioned Neutral Zone

ABSTRACT A multi-well VSP Through-Tubing campaign was conducted in order to survey 2 neighboring mature fields in the northern Arabian Gulf. Nine key wells were selected by the reservoir engineers and geophysicists from a total of more than 200 wells. The selection criteria included: (1) spatial distribution; (2) previous well data availability; and (3) completion type. At the planning stage it was estimated that 3 days (excluding night work for safety) would be required per well (one day to rig-up the mast, one day to acquire the seismic data and one day to rig-down). Local experience indicated that a single air gun would be an effective seismic source. A slimhole, monocable, single-axis geophone sonde was selected as the downhole seismic tool. The zero-offset VSP configuration, with 80 foot level-spacing from total depth to surface was adopted. A supply boat was dedicated for the duration of the campaign. The actual operation was completed in 24 days, 3 days earlier than planned. An average of 90% of the VSP levels were found suitable for first break detection, which provided accurate Time-Depth curves for all 9 wells. Geophone coupling quality is dependent on the Tubing-Casing contact. The tube wave is developed at all 9 wells; but, overall 80% of the levels were selected for VSP processing. In 5 wells, where sonic logs had been acquired, synthetic seismograms were generated which confirmed the validity of VSP reflections. The data is now integrated in a 3-D velocity model.

High quality sampling and in situ testing for deep water geotechnical site investigation: Peterson, L M; Johnson, G W; Babb, L V In: Use of In Situ Tests in Geotechnical Engineering (papers to the Conference, Blacksburg, 23–25 June 1986)P913–925. Publ New York: ASCE, 1986 (ASCE Geotechnical Special Publication No 6)

This paper discusses methods that have been used to conduct geotechnical investigations in water depths up to 2500 feet. Investigations can be conducted from supply boats, geotechnical drill vessels, and floating oil field drill vessels. In situ vanes, cone penetrometers, piston samplers and hydraulic fracture probes have been recently developed and used for deepwater investigations. These tools can be easily adapted to any type of drilling operation, are rapidly deployed and retrieved so that field time can be minimized, and are more reliable than conventional tools.

Fundamental Study on Elastic Response of Offshore Structures under Collision (2nd Report)

When offshore structures are collided with supply boats, the damages or the plastic deformations are limited within the collided membrers in most cases. The supporting structures which support the collided member only oscillate elastically. Though no damage is caused in themselves, the dynamic characteristics of the supporting structures are very important to study the motion of the collided members and to predict the degree of the damages.To clarify the dynamic.characteristics of the supporting structures, the authors employed the modal synthesis. The types of the dynamic characteristics are classified using the number of the dominant vibration modes as an index. Further, it is shown that the index can be related to direct physical parameters such as collision time and vibration period of the structure. It is also shown that these parameters can be estimated using the static finite element analysis and a simple dynamic analysis of a spring-mass model with three degree of freedom. Based on the above study, a flowchart which shows the procedure to model or to idealize the given collision problem is proposed and its validity is demonstrated through numerical examples.

Recreational behavior of onshore and offshore oil industry employees in Newfoundland, Canada

Abstract This paper discusses the results of surveys of oil industry employees in Newfoundland, Canada, working both onshore and offshore on rigs and supply boats. The surveys reveal the different recreational behavior of respondents compared to local residents, and the unique and restricted environments in which they live and work while offshore. The analysis covers the leisure time activities both offshore and onshore, and the effects of the relocation to Newfoundland upon the recreational behavior of the sample. Conclusions discuss the significance of relocation upon recreation behavior, and implications for planning, provision, and operation of leisure opportunities in coastal zone areas affected by hydrocarbon development.

Ice Management To Support The Kulluk Drilling Vessel

Abstract A second-generation drilling vessel has been constructed to extend the drilling season in the Beaufort Sea through the use of a unique hull design, mooring system and icebreaking support vessels. The unique designs of the drilling vessel, icebreakers and supply boats are described. The Kulluk vessel, designed to drill in open water or newly-formed ice, commenced drilling in August 1983. It was soon called on to cope with the most severe ice conditions in nine years. The ice surveillance and ice management procedures employed in coping with the prematurely severe 1983 ice conditions are presented. Depending on the severity of the ice hazards colour code alerts were triggered which dictated the nature of the drilling operations permissible. A pre-requisite for operations is a knowledge of which ice features present a hazard to the drilling vessel. Operationally, the hazards must be detected using radar and visual reconnaissance from aircraft or vessels. Predictions of the velocity, trajectory and time of arrival of the hazardous features are made based on plots of radar and other information. Action is taken to mitigate the hazards through the use of the four powerful icebreakers and supply boats, biased tensioning of the mooring system, disconnecting the riser or, in the extreme event, moving from the location. The icebreaking vessels work at assigned distances from the drilling unit to either break floes and pressure ridges into less hazardous features or to deflect the floes away from a collision course. The ice management system for the Kulluk was put to a severe test in its first year of operation but it performed admirably well. Introduction The continental shelf of the Beaufort Sea has long been considered to have the potential for major oil and gas accumulations. During the period 1963 to 1969, offshore permits to explore for oil and gas were issued for the majority of the shelf which extends some 125 km to 175 km from shore to water depths of 200 m. The Geological Survey of Canada's average expectations of the hydrocarbon potential of the Beaufort Sea - Mackenzie Delta area are 1347 million m3 of oil and 1865 billion m3 of gas(l). Numerous encouraging hydrocarbon discoveries have been made in the Beaufort Sea since offshore drilling commenced in 1973. The commerciality of reserves will depend on many factors such as pay thickness and other reservoir characteristics' well productivities, reservoir depth, water depth, distance from shore, environmental forces, sea bottom conditions, capital and operating costs, crude oil prices and the fiscal regime. Sea ice conditions in the Beaufort Sea are such that the drilling season from conventional ice reinforced drillships is only 3 to 4 months. The second-generation drilling vessel, BeauDril's Kulluk, was constructed to extend the drilling season by commencing earlier in spring and drilling later in the fall. This increased capability is possible because of the unique designs of the Kulluk and vessels and the ice management procedures. Environmental monitoring and forecasting and vessel performance monitoring are key activities in extending the drilling season.

Sulfide Stress-Cracking Resistance of Nitrogen-Strengthened Stainless Steels

Summary Although most materials used in oilfield operations are carbon steel or alloy steel, stainless alloys are used in critical areas where salt water, CO2, and H2S may be present. Relatively recently, a number of present. Relatively recently, a number of nitrogen-strengthened austenitic stainless steels have become commercially available. This paper describes sulfide stress-cracking tests performed on a number of these alloys. Most were found to be somewhat susceptible to cracking, depending on the stress level. It was determined that this was due to their high manganese content. The mechanism responsible for cracking was not firmly established. One commercial nitrogen-strengthened stainless steel, XM19, was highly resistant to sulfide stress cracking despite a manganese content of 5 %. This difference is attributed to the superior corrosion resistance of the alloy. Introduction Although carbon steel and alloy steel are used most often in oilfield operations, stainless alloys are used in critical areas such as pumps, valves, and downhole instrumentation housings. In many such operations, significant amounts of salt water, CO2, and H2S are present, creating severe problems of general corrosion, pitting, and sulfide stress cracking. Corrosion-resistant materials also are required in other supporting areas, such as work and supply boats for offshore platforms.Among the alloys that have been used in this area are Types 410 and S17400 stainless steels, and nickel alloy Types NO5500 and NO7750. While all these alloys have adequate strength, each has certain deficiencies. Types 410 and S17400 stainless steels both are subject to sulfide stress cracking, pitting, and crevice corrosion. The nickel alloys, although highly resistant to the environment, are considerably more expensive than the stainless steels and are less readily available.Most austenitic stainless steels have adequate corrosion resistance for oilfield operations, and are immune to sulfide stress cracking as long as they are free from 1 martensite resulting from cold work. However, they do have rather low strength, with only 30- to 35-ksi 0.2% yield strength in the annealed condition. Relatively recently, a number of nitrogen-strengthened austenitic stainless steels have become commercially available. These alloys have nearly twice the 0.2% yield strength of the 300 series of stainless steels, giving them a definite design advantage over the older alloys. Several also have other attractive features, such as excellent resistance to brine, seawater, and other corrosive environments; one alloy (Type S21800) is much less subject to galling and seizing than other corrosion-resistant alloys. All are completely nonmagnetic, even when severely cold worked. This is important for certain instrument applications, where magnetism can affect their operation seriously.This paper describes the propensity of a number of nitrogen-strengthened stainless-steel alloys to stress crack in H2S environments. The investigation was performed in two parts. The first was to determine the performed in two parts. The first was to determine the resistance of various commercial nitrogen-strengthened stainless steels to sulfide stress cracking as a function of applied stress. The second was to perform additional work on experimental alloys to determine why most of these steels were found to be somewhat susceptible to cracking. Experimental Work The test specimens used for the first phase of this work were made from commercially produced bar stock of the following stainless steels: Grades XM11, XM17, XM19, XM28, XM29, and Types S21800 and 304N. Specimens of Types 304 and 316 were included for controls. JPT P. 482

A Method for the Determination of the Reaction Forces and Structural Damage Arising in Ship Collisions

Summary Recognizing that the risk of collision between a ship and an offshore structure is high, most codes and regulatory documents require designers to assess the consequent effects on the structure. Existing requirements, which demand that all the ship's kinetic energy before impact be absorbed by the structure, are very conservative. The method outlined considers the construction and mass of both the ship and structure and assesses the variation of contact force with time, using a multidegree of-freedom lumped-mass approach. Introduction Codes of Practice and regulations relating to the design and operation of fixed offshore structures (typically Ref. 1) require that consideration must be given to those load cases associated with ship collision incidents. These documents recognize that supply ships must approach close to offshore structures and that a vessel might well be alongside and involved in operations when rapid sea-state changes occur. Such changes could induce movements in the ship that would cause fender capacity to be exceeded and the structure to be damaged. The regulations also recognize that, through errors in judgment, a supply vessel might collide with an offshore structure during power maneuvering. On the basis of such reasoning, the various regulating documents require demonstration that an offshore structure is inherently strong enough to withstand safely, though perhaps not without damage, impact of a ship of a specified displacement striking the structure at a velocity related to the sea state at which the vessel would be expected to lay off from the offshore structure. Some of the Codes of Practice give only one set of conditions related to Practice give only one set of conditions related to weather conditions - requiring that, in any incident, the damage that might be inflicted must be acceptable without leading to major collapse. Other documents define an "operating" incident (no damage may develop); this often is related to a collision when a supply vessel is maneuvering alongside. It generally is agreed throughout these regulatory requirements that supply boats will be typically of 2,500-long-ton displacement and that vessels will be expected to lay off when the sea state produces an approach speed, due to wave motion, of between 1.5 and 2 m/s. In this case, some damage can occur, but it must not be so severe that the offshore structure is placed at hazard either by structural collapse or placed at hazard either by structural collapse or excessive flooding of otherwise dry compartments. Where an "operating" impact is specified, the approach velocity of a 2,500-ton supply boat frequently is given as 0.5 m/s, which is a typical maneuvering speed. For this case, it is required that no damage be inflicted on the offshore structure. In some special cases, these requirements have been augmented by the operators to facilitate the approach of larger ships - a dedicated tanker, for instance. For these situations, additional load cases have been specified. Typically, this has involved the study of the effects arising from a 100,000-ton tanker nosing the structure at 0.5 m/s. In this case, the assessments have indicated that the bow configuration of the ship is most important, and it has been possible to define those bow forms that, in a ramming accident, might cause unacceptably high damage to the caisson structure. A similar problem can develop as the result of the impact of heavy objects dropped over the side of the structure or ships in the immediate vicinity. JPT P. 2006

The Offshore Supply Vessel as a Naval Auxiliary

In the late 1960's the expanded international search for petroleum imposed new and rigorous demands on the offshore supply vessel. These vessels entered a phase of their evolution which has resulted in a class of vessel proven to be remarkably versatile and cost effective. This paper reviews the history and development of the offshore supply boat and describes the features and capabilities of these vessels which the author believes will enable them to serve as a new class of naval auxiliary capable of multimission utilization.

Drilling and Service Contracts in Offshore Oil and Gas Operations

As onshore oil and gas deposits are becoming more difficult to locate, and as the world demands for energy continue to increase at an alarming rate, oil companies are channeling much of their exploration activities towards offshore operations, and in particular, towards operations centered off Canada's coast lines. Because of the environment, offshore drilling presents problems which are novel to the onshore-geared oil industry. J. M. Killey discusses in detail many of the considerations involved in drafting the offshore drilling contract, concentrating on problems such as the liability of the various parties; costs; scheduling; pollution; conflict of laws; etc. Similarly, he discusses service contracts (such as supply boat charters; towing services; helicopter services; etc.^ which are necessity to the operation of an offshore drilling rig. To complement his paper, the author has included number of appendices which list the various considerations lawyer must keep in mind when drafting contracts for offshore operations.

Community and Regional Development in the North

... The problems of northern development are essentially the same regardless of the region involved, or indeed in many cases regardless of the country involved. Of these problems it is generally agreed that transportation ranks first. Transportation is the single most important key to northern development - in northern Manitoba, northern Canada, or northern U.S.S.R. ... northern communities, no less than communities elsewhere in Canada, find themselves in a rapidly changing world. No longer can they mark the passing years by the arrival of the annual or semi-annual supply boat or mail run. Aircraft, radio telephone, and even taped television programs are symbolic of the degree to which change has come to the North as well, and are increasingly taken for granted by northerners. There is a comparable change in the need for northern communities. Some of these, while useful in fur trade days have become as redundant as the small elevator hamlets along the railways on the Prairies. Like them it may be better for the long-term opportunities of the residents, to encourage a migration to larger centres within the North - though this is conceded to be a delicate and difficult task. There will always have to be communities in the North, but these probably will be fewer and larger centres, better situated to meet the transportation and development needs of the present and future. It is only in larger centres that the costly and permanent service facilities now expected by all Canadians can be justified. Quite possibly smaller "camps" of relatively short life expectancy may operate out from one major centre, with a variety of commuting developed between them, as was the case for example between Yellowknife and Discovery. With the increasing capital outlay involved in establishing a modern community in the North, it clearly will be more and more difficult to abandon or relocate it in later years. To an unprecedented degree northern communities now represent long-term commitments in the area, involving very large capital investment. Only a thorough, balanced assessment of the regional potential can provide the necessary background for such vital decisions. Community and region always have been inseparably linked in northern development, but never more critically than at present.

Model Studies for an Oceanographic Ship Derived From an Offshore Supply Vessel

During the last few years, a number of operators of oceanographic research ships have considered the Gulf Coast offshore-oil-well supply vessel type for possible conversion to a research vessel. Such a ship of 155–165 ft length offers a number of attractive features; chiefly, reduced operating costs, and space for mounting portable or interchangeable equipment. The vessel's principal disadvantages reputedly are limited stability and a lack of seakindliness. An investigation of such vessels has recently been conducted by the Scripps Institution of Oceanography and the Department of Naval Architecture of the University of California. Model experiments were conducted to determine the resistance and powering characteristics, the motions in head seas, and rolling in beam seas. The transverse stability was computed for calm water and following seas. Four different hull forms were considered in these studiesa typical 155-ft-long single-chine supply boat;a round-bilge version of the same;a single-chine design developed to overcome several of the suspected deficiencies of Form 1 while still retaining the principal proportions; andan affine variation of Form 1 produced by multiplying transverse dimensions by 0.75 and increasing vertical dimensions by the same amount. It is concluded that the most serious deficiency of the vessel type is the tendency to slam in a head sea. This may limit the maximum speed in head seas. The small saving in resistance exhibited by both the narrower and round-bilge versions is insufficient to justify choosing either of these on this basis alone. In addition, both of these forms roll more severely than the two wide, single-chine forms. Finally, the increased freeboard of the third form results in an ample margin of stability. It is felt, therefore, that Form 3 provides a suitable basis for developing a research ship design.

PROPHYLACTIC USE OF MIXED VACCINE AGAINST PANDEMIC INFLUENZA AND ITS COMPLICATIONS

The fact that the recent influenza pandemic did not reach the Pacific Coast until about October 1, or more than a month after its appearance in the East, gave time to attempt a defense against it. The problems presented to Commander P. S. Rossiter, senior medical officer, of that period, were: (1) to prevent the entrance of the disease on the station, and (2) to prevent or lessen its spread and complications, should it appear among the personnel. The U. S. Naval Training Station, being located on an island in San Francisco Bay, more than a mile from either San Francisco or Oakland, made an absolute isolation possible. This was maintained during the height of the epidemic, except for a very rigidly guarded supply boat making trips to San Francisco. To accomplish the second object, daily throat sprays of argyrol, 10 per cent., were administered to every person, and steps