Navy removes waste heat boilers, steam systems and piping from cruisers

By Edward Lundquist at January 25, 2011 20:43
Filed Under: Navy insights

Navy removes waste heat boilers, steam systems and piping from cruisers

By Edward Lundquist

USS Hue City (CG 66) is undergoing the All-Electric Ship Modification at BAE Systems Jacksonville to improve the reliability and afford more efficient operation of the systems presently operated with steam.

Hue City

is undergoing the hull, mechanical and electrical (HM&E) portion of the Cruiser Modernization program, which includes removal of the waste heat boilers, and replacement of the steam-driven evaporators with new reverse osmosis (RO) systems to make fresh water.

This is a big deal.  The boilers and much of the steam supply and exhaust condensate return lines—about 70 tons going all the way up to the Captain’s cabin —are being pulled out. 

What was a good idea on paper was a bad concept in practice.  Yes, it was very efficient to remove heat from the gas turbine electric generator exhaust to make steam for hotel services and distillation to fresh water.   But these waste heat boilers use “wet steam,” which caused maintenance problems.

Hue City has completed the drydocking phase of the work where workers  removed waste heat boiler, steam separators, deaerating feed tanks, feed water tank, valves, piping, connections and fittings.  Today, new 500-gallon electric water heaters and two recirculating pumps have been installed along with new exhaust ducting that replaces the old system with the waste heat exchangers. 

The flash-type distilling systems were removed from auxiliary machinery rooms, and the steam-heated fuel oil transfer system was replaced with an electric system. The ship’s steam-heated lube oil system was replaced with electric components.  Galley steam kettles have been removed and replaced with electrically heated kettles. 

The work decreased the weight of Hue City, while creating space at the same time.

Hue City’s modernization will take about 25 weeks.  She entered drydock on Sept 29, and undocked on Jan. 11.

The majority of production work has been completed.  There remains to be completed some structural repairs and other maintenance and repairs to ship systems. This will be followed by testing and check out of all ship systems in preparation for sea trials and availability completion on March 23.

Navy estimates the average cost of each cruiser modernization at about $220 million per ship in FY2010 dollars.

The Cruiser Modernization program will systematically upgrade all 22 of the remaining Ticonderoga-class Aegis guided-missile cruisers to a better-than-new status, with state-of-the-art combat systems to meet and pace the emerging threat.  In the near term, nine of them will be upgraded to have a ballistic missile defense capability, as well.

The first Aegis surface combatant, USS Ticonderoga, was commissioned in 1983 and decommissioned in 2004, as was lead ship of a class of 27 cruisers.  The first five Ticonderoga-class CGs were retired prematurely because the cost of bringing them up to current standards was prohibitive. 

The modernized cruisers are expected to become more cost efficient to maintain, as their service lives are extended to serve in the fleet through the year 2030.  Keeping these ships combat-relevant until the end of their 35-year service lives is critical to the Navy’s force structure requirements. 

 

 

 

 

 

Comments (2) -

Now that the exhaust is going up the stack without making any steam for the ship, and the ship has to generate electricity to run the equipment that used to be powered (for free) by steam, what is the ship's increase in brake specific fuel consumption (BSFC)?  

It seems that with a Navy-standard manning complement in the engine room, the steam system could be maintained.  

Ryan |     1/26/2011 11:55:42 AM #

The reason for deciding to remove the existing steam boilers and associated equipment is stated to be because this system produced wet steam - why could not a steam superheater have been installed to produce dry steam
Best Regards Roger Hull C Eng / FIMechE / MIMarEST / FIDGTE =Pas President
Quaity Accreditation to ISO 9001 /2008

roger hull |     1/26/2011 12:20:07 PM #

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