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Steel Drums to Steelpans

Derek Gay, BSc. MSc. PhD. Department of Civil Engineering The University of the West Indies

Abstract The steelpan an innovative recycled product from steel drums originated in

Trinidad during the period of World War II (WWII 1939 -1945). Although smaller metal containers were used as musical instruments beginning in the early 1930’s, it was around 1944 that the first 55-gallon drum was used to make what has become the de facto standard sized steelpan in Trinidad and Tobago. During this period the presence of the Allied forces in the Caribbean was largely responsible for the influx of the 55 US gallon mild steel drum used principally for the shipment fuel oils.

In the years that were to follow WWII the steel drum as a shipping and storage container was applied to a more diverse range of products ushering significant changes in steel drum specifications and regulation. Unaware of the true measure of such changes, steelpan craftsmen adapted by developing unique “rating systems” to identify drums that would likely yield instruments with desirable acoustic characteristics. In this paper the findings of an investigation into the manufacture of steel drums is presented with a view to supplementing the empirical knowledge base of the steelpan maker with that which is readily available through industry regulation and standardization. The standards and regulations, which have served the steel drum industry for many years are presented and are found to provide invaluable insight into the dimensional characteristics of steel drums, but include little in respect of steel quality.

1. Introduction

The present day steelpan, a musical instrument made from 55-gallon steel drums originated in Trinidad toward the end of the period of World War II (WWII 1939 -1945). It is around 1944 that the 55-gallon steel drum was first used to make what has become the de facto standard sized steelpan.

Prior to the onset of WWII, beginning around the early 1930’s percussive instruments were made primarily from any enclosed cylindrical metal container that was available. These included containers for food products and industrial chemicals which were generally much smaller than the 55 gallon drum. As WWII progressed, the presence of the Allied/US forces in the Caribbean saw the proliferation of the 55 US gallon mild steel drum used mainly to supply fuel oils to armed forces overseas. The availability of these drums and their relatively consistent quality was probably largely responsible for it becoming the de facto standard for steelpan making.

However, in the years that were to follow WWII the supply of fuel oil drums to Trinidad and Tobago diminished to be replaced by drums carrying a more diverse range of products. Although the steelpan maker could discern the more prominent differences in the physical characteristics of the drum, it was not clear the extent to which such changes would affect the acoustical quality of the instrument produced. As a consequence individual “rating systems” were developed to identify drums that would likely yield desirable acoustic and physical characteristics. It was not uncommon for makers to develop their rating

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based on the local source of the drum, its original content, its colour or the highest number printed or embossed on its surface.

Pete Seeger [1] describes the use of such a rating system by Kim Loy Wong in which the original content of a drum is used to infer its weight, as illustrated in Figure 1.

Figure 1 A rating system in practice (LC = left centre of a 4-Bass).

Some ten years later, coming out of a more scientific domain Dennis [2], in carrying out research on drums obtained from Esso and Texaco stated:

(a) “Standard oil drums” are made from 18 gauge steel. (b) Material specifications of the steel are vague and unreliable. (c) The “standard oil drum” is made from low-grade steel of less than .15%

Carbon content. In this paper the findings of an investigation into the manufacture of steel drums

is presented. This investigation was initiated in the context of bridging the gap between empirical knowledge and that, which might be available through industry regulation and standardization for steel drums as shipping and storage containers.

The paper begins with a brief description of the history of the manufacture of steel drums and is followed by the current standards and regulations for steel drums as packaging and shipping containers. 2. The Steel Drum 1859 - 2000 2.1 The Wooden Stave Barrel: 1859 - 1900

The ubiquitous wooden barrel (traditionally made from oak staves fastened together with riveted steel belts) has served mankind since the Middle Ages. Hence, it was not surprising that Edwin Drake would have used these as his first container for crude oil. Although oil was mined by drilling in China from as early as 200 BC [3], the birth of the modern oil industry is generally associated with the drilling of wells by Edwin Drake in Pennsylvania beginning in 1859. The “Great Oil Rush” (as it is familiarly referred to) heralded an explosion in the demand for containers to store and ship crude. The first containers employed by Drake were recycled wooden stave barrels, traditionally used for the storage of wine, whiskey, fish and pickled foods. This era saw a mushrooming of cooperage companies who capitalized on the increased demand for their product. These early barrels used to transport oil throughout the 1860's were largely of non-standard capacity typically varying between 30-50 gallons. It was in the 1870's that 42 gallons became the standard container capacity as well as the “barrel” unit of measure

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for crude oil. This standard is still employed to date. As containers for oil, wooden barrels would leak excessively and anecdotes suggest that it was the leakage of 50 gallon barrels to around 40 gallons during their trip to the refinery that was largely responsible for the chosen standard.

2.2 The Steel Drum 1901 - 1938

Elizabeth Cochrane a newspaper reporter of the Victorian era (pen name Nellie Bly) is credited with the invention of the first American steel drum. Her patent for the first cylindrical steel oil drum1 was granted on December 26, 1905 [5]. She credits the inspiration for her invention with having seen steel containers for glycerine in Europe a year earlier. Her invention comprised a straight-sided cylinder utilizing an I-bar section between its top and bottom surfaces, riveted side seams, detachable rolling hoops and was constructed of 12-gauge steel. This is illustrated in Figure 2.

The first steel barrels originated in Europe at the turn of the 19th century and were commercially produced in the United States in 1902 [4] [5]. These barrels were typically geometric copies of the wooden stave barrel design with bilged sides, where riveted and/or soldered side strips replaced the wooden staves. Constructed from 12-14 gauge terne steel, they were heavy, clumsy, and were anything but leak proof. Extremely rugged, many of them lasted 20-30 years.

However, it is argued that it was Charles Draper of the Charles Draper Manufacturing Company who was largely responsible for the modern form of the present-day steel drum as his 44 US patents between 1908 and 1939 might attest.

Over the next decade, innovation and invention saw significant improvements in respect of leakage, weight and steel economy. The welded side seam was introduced in about 1907, the mechanical flange after 1910 and 16 and 18 gauge steels replaced the heavier 12 and 14 gauges used previously.

World War I (WWI) 1914-1918 saw the steel drum industry meet the challenges of having to ship acid and poison gas from the United States to the war front in Europe. Double seamed 16 gauge ICC 5-B (Interstate Commerce Commission of the US) drums were used for this purpose.

After the war, many innovations appeared, manufacturers began to use steel containers for products other than petroleum products and chemicals and increased communication between the European and American manufactures was revived.

As Nellie Bly had ventured some 18 years earlier, a well-known German drum manufacturer, of Mauser Works in Köln, Germany crossed the Atlantic to study the new steel container in 1922. Upon his return he pioneered the production of a light gauge drum (18-gauge) dubbed the “One Time Shipper” in Europe by 1924. By 1930 this light gauge drum was reluctantly accepted by the public, after companies like Shell had used it for years prior to this acceptance.

1 Although Nellie Bly used the word “barrel” as her invention and in her patent, the word drum was subsequently adopted to distinguish it from the bilge sided (curved) wooden and early steel barrels.

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Figure 2 Nellie Bly with her patents of the first American steel drum [5] This Dutch drum manufacturer Van Leer was the principal supplier for the Shell

Oil company worldwide operations and would figure significantly in later years. It would take 4 more years before this 18-gauge2 drum is approved as a “Single Trip Container” (STC) or “One Time Shipper” in the US.

2 It is significant to note that the 18-gauge drum considered as a light gauge single trip/one time shipper in the 1920’s and 30’s would become heavy drum of the 1980’s and 90’s.

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In Europe, up to about 1923, only heavy gauge steel drums were manufactured, as these were considered safe for the transportation of liquids. However, this new light weight One Time Shipper/Single Trip Container became more popular in Europe than the heavy drums as the 1938 figures for the combined German drum industry output indicated: 3 million STCs to about 1.2 million heavy drums.

Toward the end of the 1930s, the steel-container industry started gearing up for a second wartime effort. This time, however, the demands were far more stringent, requiring fuel containers for a highly mechanized war. 2.3 World War II (WWII) 1939-1945

As large transport aircraft and marine vessels became the mainstay of the war steel drums were required to be weight efficient while still being able to withstand the rigors of airlifts, drops and months of exposure to the marine environment. Although the 16 gauge 55 gallon drum, the approved ICC 5-B drum was the adopted minimum standard for US armed forces, the all 18 gauge drum was widely used during the war due to advantages associated with its lighter weight. It was during this period that the United States set up Army and Naval bases in Trinidad, beginning the influx of 55-gallon drums to the island. It is not clear whether these drums had come to Trinidad before this time. However, even if they did, these would have been made of 16 gauge and heavier steel. As a consequence, highly unlikely candidates for a percussive instrument that must be carried and enjoyed by its player. The musicians in the traditional Tamboo Bamboo and Biscuit Drum bands (precursors to the steel drum band) carried their instruments, with the traditional steel drum band being dubbed “pan around the neck” steelband. A 14 gauge and 16 gauge steel drum would weigh 89 and 50.5 pounds respectively (40.5 and 23 kilos) respectively, presenting a daunting challenge even to the most robust music maker. In addition, employing the traditional methods of sinking to such steel thicknesses would have required nothing short of the proverbial “jack hammer”.

The two most powerful organizations in respect of the standardization and regulation of steel drums would be formed during the war, The National Barrel And Drum Association Inc. (NABADA) and The Steel Shipping Container Institute (SSCI). The National Barrel And Drum Association was incorporated in 1942 and represented the interests of reconditioners who had been fully established in the manufacturing of wooden barrels and the reconditioning of both wooden and steel barrels. The Steel Shipping Container Institute (SSCI) was formed in 1944 and comprised principally the membership of the Steel Barrel Manufacturers Association. This Institution represented the interests of the manufacturers of new steel drums. During the war (WWII) the members of both associations (NABADA & SSCI) had worked together to help the government with its shipping problems – both industries striving for the limits of production, manufacturing and reconditioning millions of 14-, 16- and 18- gauge drums. However this would be short lived as these associations would wage a 20 year battle of their own over the issue of minimum gauge.

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2.4 Post WWII 1945-1981 The end of the war also signaled the loss of the industry’s biggest customer, the

US government, resulting in a downturn in steel drum and pail production. However, this was of short duration as resumption of business created a demand from industry, agriculture, and consumers. The acceleration in chemical and pharmaceutical product development and output provided new markets for steel drums and pails as demand for paints, lacquers and varnishes, adhesives, inks, foodstuffs, and other products made the steel shipping container industry one of the largest users of cold-rolled sheet steel.

Due to its satisfactory performance during the war, the all-18-gauge drum, would become the standard model of the industry and agencies such as the Uniform Classification Committee of the railroads (UFC) and the National Motor Freight Classification Board (NMFC) of the truckers, would include a minimum thickness of 18-gauge in their regulations. Nevertheless, manufacturers would turn to lighter gauge drums (20 gauge and less) since they are cheaper to manufacture making it more attractive to customers.

In 1956 the 20/18 drum (20 gauge sides and 18 gauge ends) is manufactured by SSCI members and by 1960 the 20/18 tight head drum exceeds 1 million. The use of light gauge drums was also on the increase in Canada and Europe where salad oil was being packaged in 22 gauge and lard in 26 gauge “throwaways” (STCs). The US Department of Commerce also reported that light gauge drums increased from approximately 0.3 million in 1957 to 3.0 million in 1962, the production of all 18 gauge drums dropped from 13.25 million to 10 million over the same period. A 20 year long battle would then ensue between SSCI and NABADA over the issue of minimum gauge.

1956 would also mark the first version of “The Recommendations on the Transport of Dangerous Goods” (ST/ECA/43-E/CN .2/170) by United Nations Economic and Social Council's Committee of Experts on the Transport of Dangerous Goods [6].

The NABADA would be further provoked by a collaboration of Van Leer of the Netherlands and Inland Steel Container Co. of New York in 1965, who introduced a 24- gauge “continuously corrugated body” steel drum with integral chime reinforcement, known as “Monostress”. Although this drum would prove a commercial failure in the US amidst the SSCI-NABADA battle it would be produced in Europe and a modified version of this dum remains in service to date as illustrated in Figure 3.

Figure 3 Corrugated light gauge drums typical of the original Van Leer design.

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In 1967 two of the oil giants of that time Esso and Texaco announced that they were returning to the all 18 gauge steel drums for their products, while their European based counterpart/competitor Shell continued to use the 20/18 “one time shipper”, as supplied by their principal supplier Van Leer. By 1975 the all 20 gauge drum was approved for “non-regulated” materials in the US.

The 4th International Conference on Steel Drums in Monte Carlo in 1979 was a major turning point for the American drum reconditioners (the principal evangelists of a minimum gauge) as they would hear their European counterpart, the U.K. Federation of Drum Reconditioners announce their decision to abandon the minimum gauge concept in favour of the performance oriented approach as outlined by the UN [6].

The NABADA finally capitulated on this issue when in June 1981, the DOT announced its plan to look into adopting the UN Recommendations, as the Europeans had done some years before. In 1991 the DOT officially adopted the UN recommendations. 2.5 55 gallon Drum Production

02000

400060008000

10000

120001400016000

1800020000

1982 1984 1986 1988 1990 1992 1994 1996 1998 2000Time (year)

Dru

ms

(thou

sand

s)

0.00.2

0.40.60.81.0

1.21.41.6

1.82.0

Rat

io L

ight

/Hea

vyHeavy gauge Light gauge Light/Heavy

Figure 4 55 gallon drum production in the US 1983-1998 [5] [14]

The production figures for 55-gallon steel drums in the United States between 1983 and 1998 are given in Figure 4. Recall that during and immediately after WWII nearly all drums produced were heavy gauge (18 gauge and thicker) and in 1957 only 0.3 million light gauge drums/year were manufactured reaching 3 million/year by 1962, then 15 million by 1983. This represents a dramatic and exponential increase in light gauge production in the post WWII period during which light gauge production overtook the production of heavy drums somewhere between 1962 and 1983. Despite a brief resurgence in the production of heavy drums between 1983 and 1988, light gauge drum production maintained an approximately 40 % margin over its heavy gauge counterpart over the following decade.

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3. Standardization 2000 3.1 Evolution of a Standard

The first wooden barrels used for the storage of crude oil was anything but standard in size, varying typically between 30 and 50 gallons. However, in the 1870’s the 42 gallon sized barrel evolved as the accepted standard for reasons that are still unclear to date. However, a likely contributor to this standard could be related to the ergonomic requirement that these containers had to be handled by individuals is respect of packing and moving. Indeed the curved sides of the barrel provided an efficient “rolling edge”, a concept that was included in the straight-sided cylindrical steel drum in the form of dual “rolling hoops”.

The 55-gallon “standard” steel drum implemented by Nellie Bly is also a subject of much debate. Terry [5] reports that the SSCI in an article “Why 55 Gallon Drums” in its 1968 Industry Report states that the factors involved:

“Include ratios of strength of steel plate to capacity and dimension of drum. Years of testing have shown that standard combinations of steel gage, capacity and dimensions of the 55 gallon drum maximize strength and therefore product protection and safety factors.”

However, one of the more compelling of the reasons proffered by researchers suggest that the standard could be related to the standard sized wooden barrel from which the 55-gallon drum evolved. At 42 gallons the barrel was approximately 23 inches in external diameter, 34 inches high with 19 inch diameter ends. Hence, if the same approximate maximum diameter and height is maintained but with straight (cylindrical) sides instead of the curved bilged sides an approximately 55 gallon capacity container is obtained.

Two basic styles of drums exist today: the tighthead (or non- removable head), with permanently attached top and bottom covers, and the open head (or removable head), in which the removable top head or cover is secured by using a separate closing ring with either a bolted or lever-locking closure. Expanded rolling hoops, in the drum body stiffen the cylinder and provide a low friction surface for rolling filled containers. Tight-head drums have their top and bottom heads mechanically rolled (seamed) in multiple layers (double or triple) to the body using a non-hardening seaming compound to form a joint (chime), as illustrated in Figure 5a. 3.2 ANSI, CEN and ISO

Three standards organizations currently figure prominently in the standardization of steel drums, the American National Standards Institute (ANSI), the European Committee on Standardization (Comité Euopéen de Normalisation, CEN) and the International Organization for Standardization (ISO). The ISO is a non-governmental organization established in 1947 as a worldwide federation of national standards bodies from some 140 countries. Its mission to promote the development of standardization and related activities in the world with a view to facilitating the international exchange of goods and services, and to developing cooperation in the spheres of intellectual, scientific, technological and economic activity. ISO's work results in international agreements, which are published as International Standards.

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The ANSI is the organisation responsible for standards in the USA and the CEN an institution representing 22 European member countries responsible for standards in Europe. Both ANSI and CEN are active members of the ISO.

The Steel Shipping Container Institute (SSCI) developed the standards for steel drums and pails in the United States within the American National Standards Institute (ANSI). These dimensional and construction standards have received international acceptance and have provided many advantages in the areas of filling, handling, storage and shipping. The standards cover steel drum capacities from 13-110 gallons (49.2-416 liters) and pails from1-12 gallons (2.8-45.4 liters).

The first ANSI standards for steel drums and pails were issued in 1958. Since that time significant updates and revisions were made in 1985, 1991, 1997 and 1998. From inception and up to the ANSI MH2-1991 [7] edition this standard was a collection of standards dealing with various dimensions, construction requirements and steel thicknesses for drums and pails. This edition brought the number standards to a total of 25 various types of steel shipping drums and pails using the Department of Transportation’s (DOT) specification numbers.

The ANSI MH2-1997 [8] revision represented a significant departure from the original philosophy of the standard. It represented the first time that DOT specification numbers and steel thickness specifications were not part of the standard. This was in keeping with the DOT’s revision of its own standards in 1990 to be in compliance with the UN Performance Oriented Packaging (POP) standards [9], which it mandated to be fully implemented by September 30,1996.

The ANSI MH2a-1998 [10] standard is a supplement to the 1997 Standard and includes dimensions for the 55-gallon Steel Containerizable Drums with W-style rolling hoops, as illustrated in Figure 5b. The “containerizable” steel drum represents an innovation in which the maximum external diameter of the drum is reduced from 595 mm (23 7/16 inches) to 585 mm (23 inches) while retaining its internal diameter and nominal capacity of 55 gallons. This innovation allowed the new drum to be packed four abreast in inter-modal shipping containers meeting ISO 668-1988, Series 1 Freight Containers - Classification, Dimensions and Rating. Up to 80 of these new drums (palletized and stacked two-high) will fit into a 20-foot freight container, which is 4 to 12 drums more than un-palletized and palletized domestic or export drum.

Steel thickness and metal quality do not form part of the current standard. However, drums are typically fabricated from cold-rolled sheet steel in a range of thicknesses from 2.4 mm (0.0946 inches, formerly 12-gauge) to 0.292 mm (0.0115 inches, formerly 29-gauge) as indicated in Table 1. Table 1 Gauge No. and Sheet Steel Thicknesses Gauge 12 16 18 19 20 22 24 26 28 29inches .0946 .0553 .0428 .0375 .0324 .0296 .0209 .0159 .0129 .0115mm 2.40 1.35 1.09 .960 .823 .648 .531 .404 .328 .292Nominal 2.4 1.4 1.1 1.0 0.8 0.7 0.5 0.4 0.3 0.3

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Figure 5a ANSI MH2 1997 Conventional 55 gallon drum specifications 4. Regulation 2000 4.1 The United Nations

The United Nations (UN) Recommendations on the Transport of Dangerous Goods [6] are addressed to governments and to the international organizations concerned with the regulation of the transport of dangerous goods. The United Nations Economic and Social Council’s Committee of Experts on the Transport of Dangerous Goods have prepared them, and were first published in 1956 (ST/ECA/43-E/CN .2/170). They have been regularly amended and updated at succeeding sessions of the Committee of Experts. These recommendations contain "General Recommendations on Packing," which details packaging requirements, types of packaging, and marking and testing requirements. Members of the UN Committee are committed to adopt these recommendations into their respective nation's transportation regulations as closely as possible to the original, although differences are permitted.

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Figure 5b ANSI MH2a 1998 Containerizable ISO 55 gallon drum specifications

The UN recommendations are not regulations per se, but guidelines for regulations. Yet they are usually part of the law in the country of export or import if not both. For example, Canada has adopted the UN recommendations into its Transportation of Dangerous Goods Act and Regulations and Related Performance Packaging Standards, while Mexico has nearly completed the process of writing the POP standards required under its hazardous materials transportation law of 1992. Two international codes do have the force of law for member states: the International Maritime Organization's (IMO) International Maritime Dangerous Goods Code (IMDG Code) governing hazardous materials transportation by water and the International Civil Aviation Organization’s (ICAO) Technical Instructions for the Safe Transport of Dangerous Goods by Air. These two codes have adopted the UN recommendations.

In the United States decades-old DOT design specifications (such as the DOT-17E, -17H, and -17C containers) have been replaced by new Performance-Oriented Packaging Standards, based on the United Nations' Recommendations on Transport of Dangerous Goods. The reasons for this shift were harmonization of packaging requirements with international regulations and development of package safety criteria based on the performance of the container rather than on its design. This has entailed a

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complete restructuring of the way packagings are specified. The SSCI's manual “Understanding HM-181 for Steel Drums” [11] summarizes the DOT regulations found in Title 49 of the Code of Federal Regulations [12] as they pertain to steel drums and pails. 4.2 UN Markings

Packagers must now provide their drum and pail suppliers with the following information:

(i) Packing Group, (I, II, III, see Table 2) (ii) product vapor pressure (if liquid), (iii) net mass (if solid), and (iv) specific gravity (if liquid). The steel drum manufacturer marks the container, after having performed the

following UN performance tests [13]: (i) drop, (ii) leak proofness, (iii) stacking, (iv) hydrostatic pressure (if liquid), and (v) vibration.

The results of these tests are then translated into a rating system, which forms the permanent marking and labeling for the drum.

Two types of markings exists the Durable and the Permanent marks [9]. Sample marks for a tighthead 55 gallon (208 litres) 20/18 drum with a nominal 1.1-mm-thick head and bottom and 0.8-mm body manufactured in 1998 and authorized to carry a Packing Group II or III liquid with a specific gravity of 1.8 or less and with a product vapor pressure of 300 kPa (or less) at 55°C is marked as illustrated in Figure 6; where, UN = United Nations, 1 = drum, A = steel, 1 = tight head, Y = Packing Group II or III, 1.8 = specific gravity (relative density of material to water), 300 = maximum hydro static pressure tested in kPa, 98 = year of manufacture, US = country of manufacture, XXXX = manufacturer's number of symbol, and 1.1/.8/1.1 = thickness of top, body and bottom in millimeters.

A sample mark for an open-head 55 gallon (208 litres) steel drum with nominal thickness 1.1 mm manufactured in 1998 and authorized to carry a Packing Group II or III liquid with a specific gravity of 1.2 or less and with a product vapor pressure of 100 kPa (or less) at 55°C is marked as illustrated in Figure 7 (top).

A sample mark for an open-head steel drum with nominal thickness 1.1 mm manufactured in 1998 authorized to carry a Packing Group II or III solid with a gross mass of 425 kg (or less) marked as illustrated in Figure 7 (bottom); where UN = United Nations, 1 = drum, A = steel, 2 = open head, Y = Packing Group II or III, 425 = maximum gross mass in kg (net mass of solid plus mass of drum), S = solid, 98 = year of manufacture, and 1.1 = thickness of millimeters. A typical UN mark on a tuned bass steelpan is illustrated in Figure 8.

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Figure 6 UN Performance Oriented Packaging drum markings – tight-head drums

Table 2 UN Recommendations: Packing Groups Packing Group Degree of Danger Marking

Group I Great X Group II Medium Y Group III Minor Z

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Figure 7 UN Performance Oriented Packaging drum markings – open-head drums Figure 8 UN Performance Oriented Packaging drum markings on a Bass steelpan

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5. Conclusions (a) The steel drums upon which the inventors of the steelpan hammered were up to 100

% thicker (16:20 gauge) than those which became the norm in Trinidad and Tobago from the early 1970’s to the present.

(b) The majority of drums coming to Trinidad are of the single trip variety (no returns no refund!) whose construction standards are optimized to fulfill the safe transport of its contents over a single pass. The popularity of this Single Trip Container (20/18 and lighter gauge drum) resulted in a significant reduction in the availability of heavy gauge drums suitable for recycling into quality steelpans. Over the past two decades the ratio of light to heavy gauge drums in the US averages 1.5. Furthermore, the greater proportion of these heavy gauges remains in their country of manufacture to be reconditioned and recycled.

(c) The UN Performance Oriented Packaging (POP) standards and regulations, adopted by the steel drum industry can be invaluable to the identification of drums in respect of their potential for recycling into steelpans. However, adherence to such standards is not in itself a guarantee of their suitability.

(d) POP standards and regulations do not adequately address the characterization of the steel itself.

6. References 1. Pete Seeger 1961, The Steel Drums of Kim Loy Wong, An Instruction Book, Oak

Publication Inc. New York, 1961. 2. Ron Dennis 1971, A preliminary investigation of the manufacture and performance

of a tenor steel pan. West Indian Journal of Engineering 3(1), 32-71. 3. Stephen Howarth 1998, A Century in Oil : The Shell Transport and Trading

Company 1897-1997. Weidenfeld & Nicolson Ltd; March 1998 4. Richard B. Norment 1997, The Wiley Encyclopedia of Packaging Technology,

Second Edition, John Wiley and Sons 5. Pamela Terry 1991, Fifty-Five Gallons The History of Steel Drum Reconditioning,

NABADA - The Association of Container Reconditioners. 6. ANSI 1992, ANSI MH2-1991, American National Standards Institute, New York. 7. United Nations 1999, United Nations Committee of Experts on the Transport of

Dangerous Goods, Recommendations on the Transport of Dangerous Goods, 11th edition., United Nations, New York and Geneva 1999.

8. ANSI 1997, American National Standard For Steel Drums and Pails, ANSI MH2-1997: American National Standards Institution.

9. ANSI 1998, ANSI MH2a-1998, Supplement to ANSI MH2-1997: SSCI, 1998. 10. SSCI 1998. Understanding Performance Oriented Packaging (POP) for Steel

Drums and Pails, The Steel Shipping Containers Institute (SSCI), Third Edition, July 1998, http//www.steelcontainers.com.

11. SSCI 1993, Understanding HM-181 for Steel Drums, Washington, DC, 1993.. 12. U.S. Department of Transportation (DOT), Code of Federal Regulations, Title 49,

Parts 100-199 (Oct. 1993). 13. SSCI 1999,. UN Testing Procedures, March 1999, Revision 2.0 14. US Census 1997, US Census Report MA34K Steel Shipping Drums and Pails.