Most New Yorkers probably don’t think twice when they flush the toilet, and they certainly don’t connect their action with Red Hook, the inconspicuous gray 350-foot tanker that shuttles busily every day from one part of New York harbor to another.
|United Nations building at First Avenue and E. 42nd Street looms up off the starboard bow.|
But that’s because they’re ignorant of a fact of life in the Big Apple. Six of the city’s 14 wastewater plants aren’t able to finish processing the sewage that ends up in them, and as a result the city’s Department of Environmental Protection (DEP) employs Red Hook and two sister vessels to transport liquid sludge to the facilities that can handle them.
|Capt. Chris Reil at the helm of Red Hook on the East River. DEP’s three sludge vessels are a common sight from the Manhattan shoreline, and they travel some scenic urban waterways when they’re not loading or unloading at water treatment plants.|
Red Hook, constructed by Keppel AmFELS in Brownsville, Texas, and commissioned in January, cost $30 million and is the first DEP vessel built solely to carry sludge from one plant to another. Its predecessors were built for dumping at sea, which has been banned for two decades.
Designed by Gibbs & Cox, of New York, Red Hook incorporates many improvements over the older vessels, notably an integrated bridge control and monitoring system from Kongsberg. The new Electronic Chart Display and Information System alone is “probably the biggest difference” on the vessel, says its captain, Chris Reil. The bridge also includes full cargo and engine room controls and there are bridge control repeaters on both bridge wings.
The vessel is also more maneuverable than the other tankers in the fleet. For a start, there is more horsepower. Twin Wärtsilä medium-speed diesels drive 8-foot, four-blade propellers via Masson-Marine MM W20000 reduction gears, and there is a Thrustmaster fixed-pitch bow thruster. The rudder turn is 45 degrees compared with 35 degrees on the other boats.
|Red Hook meets another sludge vessel, Newtown Creek, built in 1968, on a wintry New York morning. The vessels share an unusual feature, kingposts linked by a gantry-like arrangement that disperses vapors from the cargo well above the level of the bridge.|
That makes a big difference on a vessel that spends much of its time maneuvering in and out of docks. Red Hook‘s longest transit is just 26 miles, from Hunts Point to Jamaica Bay, and the DEP estimates that in the course of a year its three sludge vessels complete about 3,200 dockings or undockings. “That’s basically what the boat does all day,” says Kevin Byrnes, chief of operations for the department’s marine section.
Red Hook‘s size â€” cargo capacity is 150,000 cubic feet of sludge, in eight tanks â€” makes it more efficient than the smaller vessels in the fleet. Cargo handling is also easier. The pump rooms on the older vessels were built into the bow; they were designed for ballasting in the days of ocean dumping and were only converted later to pump sludge. Red Hook‘s pump room is aft, which assists with head on the cargo pumps’ suction. The pump room is also closer to the engine room and cargo control room.
The tanks take about two hours to unload, and a scavenger pump strips the tanks clean. On the older vessels, there is typically a couple of feet of sludge left after pumpout.
Two other changes based on lessons learned from the older vessels are the addition of an extra access trunk on the main deck (for troubleshooting problems with valves) and a bulkhead door between the engine room console and the steering room. Previously, the crew had to go up to the main deck, open a watertight door, and climb down a steep ladder into what was basically a watertight space.
Repositioning the cranes
Another improvement is the location of the two North Pacific cargo-handling cranes along the centerline instead of to port and starboard. “If the port crane was down, we could only dock starboard-side to,” says Byrnes. “That would be problematic for the captains â€” they like to always dock the vessel against the tide. Now if we have one crane down we can still use the other crane.”
The crew’s only real cause for regret is the switch from the graceful, rounded sterns of the older boats to a square stern, which means captains can’t push off the docks as they used to. Byrnes says with a rueful chuckle that the DEP wanted a rounded stern and he hasn’t quite figured out at what point in the process it disappeared.
The DEP sought and obtained ABS classification for the new vessel. Red Hook, however, is not subject to regular U.S. Coast Guard inspection. It is not carrying a regulated cargo, it operates in inland waters, and since it is operated by the city it is not carrying freight for hire.
The award of the contract for Red Hook to Keppel AmFELS, a rig builder, was unusual for a vessel of this type, although Keppel had previously built a much smaller boat for DEP â€” Cormorant, a 120-foot debris skimmer commissioned in 1993 and powered by twin Schottel high-volume, low-velocity jet drives. Byrnes says only two yards bid on the sludge vessel, which was under construction for three years. The reasons are not clear, although many mid-tier shipyards dislike the paperwork involved in government contracts, and yards in general were not hurting for orders at the time.
|AB Douglas Royal opens a valve to discharge sludge from the hold. Red Hook is the DEP’s first vessel purpose-built to carry treated sludge from one wastewater plant to another; its predecessors were built for ocean dumping.|
This year, with mid-tier yards desperate for work, DEP received five bids when it sought a yard to build three slightly smaller sludge ships for delivery over the next four years, a contract with an engineer’s estimate of $91 million. Keppel AmFELS bid on these vessels too, as did Aker Philadelphia Shipyard, Bollinger Shipyards, Fincantieri Marine Group and VT Halter Marine.
The new vessels will be 290 feet long with a cargo capacity of 140,000 cubic feet. They are designed to operate in shallow water, such as the Passaic River in New Jersey or Newtown Creek off the East River in New York. The biggest change calls for submersible pumps in each tank, and the new boats will lack one feature of the current ships: the old-fashioned, gantry-like kingposts amidships that vent vapors above the level of the bridge (and no, there’s no discernible odor on board).
Red Hook‘s crew consists of a captain, chief, assistant engineers, a mate and two mariners. Crews work a 40-hour week divided into three shifts, one 14 hours and two 13 hours long. And there’s an unexpected bonus to working on a sludge vessel on a cold winter’s morning on the East River. The sludge comes on board heated to 105 degrees. â€¢