Page 27: of Maritime Reporter Magazine (January 1973)

The Delaware Bay Terminal -An Environmental Plus!

Capt. Robert I. Price, USCG*

The lower Delaware Bay is quite possibly the most desirable location on the East Coast of the U.S. for development of a deepwater terminal. From such a terminal oil could be readily delivered by pipeline to the complex of seven major oil refineries along the Dela- ware south of Philadelphia, for convenient dis- tribution to the belt of fuel-hungry industries stretched from New York to Baltimore. Tak- ing advantage of natural canyons which ex- tend into the bay from offshore, it is feasible, according to the Army Corps of Engineers, to create a channel for the entry of deep-draft bulk cargoships to a terminal located inside the bay on the Delaware side.

Aside from the economies involved, which are considerable, a properly designed and con- trolled terminal at the entrance to the channel is fully justified on the grounds of ship and environmental safety. Without a terminal, there is only the prospect of an enormous ex- tension of the present methods of delivering oil to the Delaware River refineries. The con- sequence of refusing the terminal is intensified marine traffic with increased likelihood of casualties and spillage of oil.

The Delaware River ship channel has a pro- ject depth of 40 feet at mean low water. This channel was dredged in World War II when a deep-draft ship was one drawing 30 feet. The channel is 800 feet wid

It is subject to silting and its depth is under continual survey .by the Corps of Engineers.

The project depth of 40 feet has not actually been fully attained. There is a rock pinnacle at one side of the channel at Marcus Hook whi'ch must be avoided. The depth at that point is 35.8 feet. The channel also has several anchorages along its length—sidings into which ships can be diverted in the event of de- lays in the channel or lack of pier berths. How- ever, only two of these anchorages have been dredged to the project depth of 40 feet and then, not over their entire area. Although these anchorage projects had Congressional approval 10 years ago, they have y

Tankers with saltwater drafts of up to 54.8 feet now enter Delaware Bay and anchor. If necessary to reduce draft to transit the Dela- *Capt. Robert I. Price, U.S. Coast Guard, is Cap- tain of the Port, Philadelphia. The opinions or assertions contained herein are the private ones of the writer and are not to be construed as official or reflecting the views of the Commandant or the

Coast Guard at large. ware River channel, they transfer some of their oil cargo into a fleet of barges in the open roadstead of the bay. Several barge loads may be required to reduce a tanker's draft suffici- ently for the river run. To change the saltwa- ter draft in one of these tankers one inch can require removing about 200 tons of oil. This lightering represents added operating expense of itself and in delaying movement of the tank- er. Each lightering event entails a risk of spil- lage, while coupling, during cargo pumping and while uncoupling barge from tanker. The tanker must then negotiate the river to the re- finery to discharge the remainder of the cargo.

In order to do this safely, knowledge of the timing and range of the tide is vital. The tidal range in the Delaware River from mean low water to mean high water is about six feet.

The tidal differential can be greater or less and can be delayed or advanced depending up- on the force of the wind and its direction, amount of rainfall, and the phasing of sun and moon. The effect of these variables must be anticipated by the pilots of the Delaware River and Bay, to whose competence a commendable safety record can be ascribed.

Ships With drafts close to the 40-foot chan- nel depth lie at anchorage in Delaware Bay awaiting the rise of the tide, then transit the channel "on the tide," taking advantage of the increased depth. The movement occasionally involves close timing to put a ship at the re- finery terminal so that the cargo can be dis- charged ashore, lightening the ship before the fall of tide. Ships entering on the same tide come upriver relatively close together; it is 12 hours till the next favorable tide. If blockage of the channel were to occur when a number of vessels had started upriver on the same tide, the lack of full depth in the anchorages could very well prove a significant deficiency.

If deeper draft ships attempt to navigate the

Delaware, there are many problems that they encounter. These nautical facts reveal the fine- ly balanced state of present operations of large ships in the Delaware: —Reducing draft simultaneously increases freeboard, exposing more structure to the force of the wind and making a tanker less control- lable. —If the ship does not maintain good speed, the tide could begin to recede before reaching the refinery, but there may be a limiting condi- tion. Higher speed in a channel, say—to make up for a late start—leads to a hydrodynamic phenomenon called "squat," which can cause a ship to run deeper and perhaps to strike bottom. —The channel has several pronounced bends.

A ship does not "corner" like an automobile but slides rather like a skier. Longer, larger ships obviously will have difficulty staying in the channel. —If the course is held close to the side of the channel, a ship can become difficult to steer. Passing close to another ship can also cause problems of ship control. —The river current averages 1.8 knots ordi- narily. In adverse weather conditions, currents may attain 3.7 knots. —In obedience to Archimedes's law, ships increase in draft as they go into freshwater— gaining one foot per 35 feet of the saltwater draft. The freshwater transition point in the

Delaware is near Marcus Hook, 80 miles from the ocean, in the center of the refinery com- plex.

If these problems exist, why not simply dredge the channel deeper? Why! —because it is impractical to do so. In a recent address before the Port of Philadelphia Maritime So- ciety, Maj. Gen. R.H. Groves, U.S. Army, Di- vision Engineer, Corps of Engineers, stated: "Deepening this channel to 45 feet would in- volve the removal of 190 million cubic yards of material at an estimated cost of $300 mil- lion. If we were to take it to 50 feet, we would have to remove some 330 million cubic yards at a cost greater than of a billion dollars.

Of course, we would have to find suitable dis- posal areas for all this material and, as many of you know, we are fast running out of places where we can put the relatively small amounts of material we are presently excavating to maintain this channel at 40 feet."

Not only is the cost prohibitive, there is the effect upon the natural water table to consider.

Deepening the channel will move the salt/ freshwater interface upriver and inland, to the detriment of the aquifers supplying the agri- cultural economy of southern New Jersey.

Presently, most oil reaching U.S. East Coast ports by sea comes from either Texas, Louisi- ana or Venezuela. However, there are well- documented predictions of a deficiency of oil to satisfy the steadily increasing energy de- mand in the U.S. in the next 10 to 15 years.

National Petroleum Council (NPC) projec- tions show oil demand rising by about 4 per- cent annually. Foreign oil will be imported to cover these demands. In 1970, foreign oil was 23 percent of domestic demand. Projec- tions by NPC indicate oil imports rising to 39 percent of demand in 1975, 47 percent in 1980, and 57 percent in 1985. This will equal 25 per- cent of total U.S. energy use and much of it will come from the Middle East.

This oil will be delivered by tankers of much greater size than heretofore seen in U.S. ports, (Continued on page 31)

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