Document x1oVR8yox7XKOVKLNVqp227mJ

Fm. 23-1 (332 i 126) 33-323 NEWPORT NEWS SHIPBUILDING AND DRY DOCK COMPANY FILE NO_____________57 3 NEWPORT NEWS, VIRGINIA December 8, 1963 MEMORAJNDUM For Mr. L. C. Robertson Subjects Single Screw Bulk Oil Tanker* for Humble Oil & Refining Company, our Hull 57 3 Ventilation and Heating of Wheelhouse and Chart Room References . (a) Humble Oil end Refining Company's letter 0.3 438-7 p* dated November 30, 1965 In answer to reference (a), vessel specifications. Section 403, page H-80, requires Hheelhouse and Chart Room to be ventilated with, mechanical supply and natural exhaust with a 15 minute rate of change. Section 415, page H-83, requires "Suitable convectors with guards are to be provided for the Diesel Generator Room, steering Gear Space, Bridge and similar working spades, which are not heated by the combined air conditioning and heating system." Ventilation and heating for the wheelhouse and Chart Room, our drawings 725-8735 and 265-3339, are strictly in accordance with the vessels' specifications and owner approved ventilation and heating diagrams and calculations. Convectors were selected to heat the wHeeihousa to 60F. and the chart room to 70P, and this basis of selection was approved. There are four convectors in the Wheelhouse rated at 42,8Q0 BTU/hr. total. There are three convectors in the Chart Room rated at 39,900 BTD/hr. total. On previous Esso ships, out Hulls 540-41, the Wheelhouse (about the same size as on Bulls 573 and 576) was heated by two steam convectors rated at about 20,000 3&/hr* total. Neither mechanical nor natural ventilation was provided. Fresh air was secured by opening doors or windows. The Chart Room on these vessels had mechanical supply air, but was heated by^eteam convector# rated at 3,000 BTST/hr. Both rooms were handled strictly in accordance with the vessels' specifications* Hulls 519-20 had similar arrange ments with larger convectors. Hone of these ships have reported heating troubles. / 2 MEHQRMJD'tM For Hr, I. c. Robertson December 8, 1965 in accordance with the specifications and with approved diagrams and plans* there were no filters provided for the ventilation system serving the Wheelhouse and the Chart Room on the ESSO HOUSTON* Also# tire weather air intake is forward of the stack. toy change from the installed ventilation and heating in the vsheelhquse and Chart Room is not contractor responsibility. However, if the owner is witling, to pay for improvements, a filtered ihieit box can installed bvdr'the fan in its'present'location* by removing the s^shrOom and substituting a bellmouth. ; . fhe- convection pattern for the- two convectors, on the. forward bulk&eaI of .tins/''^h^thoasO -cfR ^ improved by the .addition of baffles in tfee-joiner-^rk- enclosing- .the eCnveCtOrs,/ and by relocation -of' ' . . the inlets in the jo-indr--work-at. the-.base-of-.'the convectors to. allow a'more ^obstructed - fXbw*. ` we .soasiderrthat if all' four convectors are tased^ with siCam solely - Valves either- full open or partially Open#enpgh Circulation can be.-obtained to reduce the stratification problems which have been reported. -- 4 ,w 3W ' i - Carbon duplicate herewith 1,.** EDH-B, Hr. J. E. Harding 1 * Hr * G. B Johnson C. B. Coe EXX-MOR-006278