• ITVI.USA
    17,113.070
    186.890
    1.1%
  • OTRI.USA
    28.200
    0.000
    0%
  • OTVI.USA
    17,079.400
    184.170
    1.1%
  • TLT.USA
    3.090
    0.190
    6.6%
  • TSTOPVRPM.ATLPHL
    2.630
    0.060
    2.3%
  • TSTOPVRPM.CHIATL
    3.080
    -0.090
    -2.8%
  • TSTOPVRPM.DALLAX
    1.180
    -0.060
    -4.8%
  • TSTOPVRPM.LAXDAL
    3.210
    -0.070
    -2.1%
  • TSTOPVRPM.PHLCHI
    1.630
    -0.090
    -5.2%
  • TSTOPVRPM.LAXSEA
    3.360
    0.070
    2.1%
  • WAIT.USA
    121.000
    1.000
    0.8%
  • ITVI.USA
    17,113.070
    186.890
    1.1%
  • OTRI.USA
    28.200
    0.000
    0%
  • OTVI.USA
    17,079.400
    184.170
    1.1%
  • TLT.USA
    3.090
    0.190
    6.6%
  • TSTOPVRPM.ATLPHL
    2.630
    0.060
    2.3%
  • TSTOPVRPM.CHIATL
    3.080
    -0.090
    -2.8%
  • TSTOPVRPM.DALLAX
    1.180
    -0.060
    -4.8%
  • TSTOPVRPM.LAXDAL
    3.210
    -0.070
    -2.1%
  • TSTOPVRPM.PHLCHI
    1.630
    -0.090
    -5.2%
  • TSTOPVRPM.LAXSEA
    3.360
    0.070
    2.1%
  • WAIT.USA
    121.000
    1.000
    0.8%
American ShipperShipping

Maritime History Notes: Tug barge units

Most barges in the early days began their use as sailing ships.

   Barges seldom make the headlines, and so we rarely hear about advances in barge transportation. However, today about half of the U.S. Merchant Marine is made up of integrated tug barges (ITBs) and articulated tug barges (ATBs). While we have fewer than 200 ships under U.S. flag, there are over 22,000 river barges plying American waterways. 
   Today tug barge units are employed in the transport of containers, roll-on/roll-off cargoes, oil, chemicals, liquid natural gas (LNG), ammonia, and dry-bulk commodities such as coal and grain. In addition to the coastwise trades, these vessels are regularly employed on transatlantic and transpacific voyages. Some can carry the combined deadweight cargo of three Liberty ships; however, today’s tug-barges require a crew of only nine to 12, whereas one Liberty had a crew of about 50.
   The evolution of these vessels is quite interesting. It was more than 150 years ago when steam power began to replace sails. Most barges in the early days began their lives as sailing ships. To adapt to their new roles many were dismasted, or had their masts cut down and rigged as schooners. The power to pull the barge was usually supplied by a steamship, not a tug boat. 
   One of the most famous steamship-barge combinations was operated by the Anglo American Oil Co. and affectionately known as the “horse and cart.” The horse was the 8,800-ton steam tanker, Iroquois, while the cart was the 9,250-ton barge, Navahoe. The steamship-barge was employed in the transatlantic trades for many years.  
   Many similar horse-and-cart units were owned by industrial carriers and employed in the bulk trades, such as the schooner barge Dykes of Alcoa Steamship Co. During World War I, many tug companies built large oceangoing, high horse power tug boats, which used traditional towing arrangements. That is a tug towing a barge astern on a towline, or hawser. This method is still quite common today.  

The Carport, which was built in 1950 for Cargill, became the first integrated tug barge.

   The great advance in towing occurred in 1950, when a specially built barge was mated with a specially built tug. Cargo Carriers Inc. of Cleveland, a subsidiary of Cargill in Minneapolis, pioneered this concept. The vessel, described as an “integrated tug barge,” was built at Sturgeon Bay Wisconsin by the Christy Corp. It was intended for service on the Great Lakes and the New York Barge Canal in the summer, while during winter when ice closed the trade, the vessel would sail between New York and San Francisco via the Panama Canal. As one might expect, its intended cargoes would be grain and grain by products.
   The vessel consisted of two components. The 4,400-deadweight-ton barge, G-1, was 268.5-feet long and 43.5-feet wide. It had a “ship shaped” bow and a large “U” shaped recess in the stern to offer a tight fit for its power unit, named Carport, which was held in place with massive turnbuckles. The single screw Carport was 64.5 feet in length and measured 99 gross tons. A 1,280 horsepower Fairbanks-Morse engine supplied the power to propel the craft at 13 knots. The vessel was fitted with a hydraulic wheelhouse, which could be lowered when passing under low bridges.
   Although the Carport proved successful, the availability of inexpensive surplus World War II-built tonnage, including tugs, barges and Liberty ships, also proved to be an efficient, economical source of carrying capacity. For example, Eastern Gas and Fuel converted its six Liberty ships to barges and contracted Moran to tow them using the traditional hawser method.
   As U.S. labor costs in the coastal trades increased during the 1960s, and towed barges continued to suffer substantial delays during heavy weather, the idea of a tug pushing rather than pulling a barge was examined again.

A tug prepares to be joined to a chemical barge.

   Even though very large oil barges of up to 250,000 barrels of capacity were built and put into service, the hydrodynamic disadvantages of towing them were becoming highly evident. This brought a return to the ITB concept, where a barge is pushed rather than pulled to enhance both speed and maneuverability. Because of the lower manning requirement for a tug, ITB owners could also expect a substantial reduction in operating costs. The tugboat designed to act as the open-ocean pusher, however, looked very little like its kin. Some pushers made use of a catamaran hull with inner-hull contours that accepted a “tongue” from the barge, while others were monohulls that had indentations on each side to accept “forks” from the barge. In each case, the idea was to physically lock the two units together securely for a safe ocean passage.

The Petrochemical Producer, an ATB employed in the chemical trades.

   Most ITBs were successful, but not all shipowners were willing to gamble on the technology.  For one thing, it was often difficult to separate the ITB tug from its barge—for example, when dry-docking was required, and once separated, the tug often proved it was not designed to operate independently.

Left: The Martha R. Ingram in the process of being joined to its barge.
Right: The vessel underway in the Gulf of Mexico.

   In the late 1960s, Ingram Ocean Systems inspired by the success of the Carport built two 34,000-ton ITB units, the Carole G. Ingram and Martha R. Ingram, which were delivered in 1971. As with all new ventures, there are always teething problems, and on Jan. 10, 1972, at Port Jefferson, N.Y., the Martha R. Ingram broke in two sections. But once repaired, and lessons learned, both units continued with long and productive lives.
   During the 1970s, numerous advances were made, and in recognition of the difficulties in operating ITBs, the articulated tug barges, or ATBs, were developed. The difference being coupling systems were developed to mate a tug to its barge, while allowing the tug to roll and heave with the barge but to pitch independently. 
   So, when you go down to the waterfront and bemoan the fact that those graceful and impressive ships of yesteryear no longer ply the waves, have faith. Know that they have been succeeded by tug-barge units that bring us the containers of freight and the fuel we need at a far less expensive cost. 

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