A chain-of-title search for this property revealed Deed AM, Book 22, 209 (December 14, 1831):
“Buildings, Spermaceti Works, Oil Factory, Blacksmith Shop, Stable Coach House, Tool House, Carpenter’s Workshop, and Wharf, Screw Dock, & Lot…together with all machinery, fixtures, tools, utensils, implements of the said Spermaciti & Oil factory, and 40 Screws & Fixtures & apparatus to the Screw Dock, & other buildings, wharves, docks, landings, landing places, streets, & ways.”
According to Joseph Blunt, editor of the American Register, the Kensington Screw Dock Company was formally incorporated in 1832-33:
“That JAMES MOTT, WESTERN C. DONALDSON, SAMUEL C. BUNTING, THOMAS W. MORGAN, JACOB T. BUNTING, WILLIAM FENNELL JR., THOMAS S. RICHARDS, THOMAS M. COFFIN, and JONATHAN PALMER, are hereby appointed commissioners of the Kensington Screw Dock Company.”
James Mott and Thomas M. Coffin are the husband and brother of famed abolitionist and women’s rights advocate Lucretia Mott (buried nearby at the Friends Fairhill Burial Grounds, 9th & Cambria Streets). The Coffins (including Lucretia, Thomas and their father) moved from Nantucket, MA, to Philadelphia, originally as commission merchants. James Mott was a teacher at Nine Partners, New York, where he met Lucretia Coffin. James Mott joined the Coffins in Philadelphia and later, married Lucretia.
Soon after the erection of the Kensington Screw Dock, it was advertised for sale (Dec. 13, 1833):
“Valuable Real Estate. Kensington Screw Dock. Will be sold at the Merchants’ Coffee House, Philadelphia, on the 19th of December next, at 7 o’clock in the evening,
“All that valuable property known as the “Kensington Screw Dock, situated on Penn-street, Kensington, containing in front on said Penn-st. 150 feet, and containing that width into the river Delaware; together with all the improvements, consisting of a new brick building, 50 feet square, with all the machinery therein contained, forming the most complete establishment in the country for the manufacture of sperm oil and candles; a frame building 75 feet by 20 feet, both fronting on Penn-street. Also, blacksmith’s shop, tool house, stable and coach-house, carpenters’ shed, &c.; together with the screw dock, in complete order, and which has been in successful operation for the last two years, having raised during this time one hundred and fifty sail, from canal boats to ships of 600 tons burthen. This plan has advantages over every other for the purpose, is simple, and not liable to get out of order; an appropriation of $200 from its earnings being sufficient to keep the whole property in repair. It is secured by patent; and by an act of the legislature passed at the last session. A company can be incorporated for conducting the business. With constant employment it is capable of earning $10,000. The receipts for the present year have been $4,000; and from the whole property exceeding $5,000; the expenses for labor, hire of horses, about $1,000.
“Upon the lot there is sufficient room without interfering with the operations of the screw dock, for the erection of buildings of any description, particularly for any manufactory where steam power might be required.
“This property presents the greatest advantages for conducting the whale fishery of any manufactory where steam power might be required.
“To the capitalist it affords an opportunity of safe investment, being situated in an highly improving district; and in the vicinity of the termination of the Delaware and Schuylkill and Trenton Railways.
“A tenant can be procured who will take the property upon lease of seven or ten years, and give security for the rent.
“Any further information can be obtained upon application to Thomas M. Coffin, upon the premises, or to Shober and Bunting, Philadelphia.
“Lippincoott, Richards, & Co. Philadelphia, Nov. 25th, 1833.” 
This advertisement brought a buyer:
“The valuable property known by the name of the Kensington Screw Dock, was sold at the Merchants Coffee House on Thursday last for $40,400. It was purchased by Mr. Thomas W. Morgan for a New-Bedford House, whose intention is to erect on the premises an extensive Manufactory of Spermaceti Oil and Candles. It is intimated that the enterprising owner after seeing the manufactory in full operation intends establishing a line of whaling ships which are to bring the crude oil direct to his wharf at Kensington.” 
The purchaser, Thomas W. Morgan, was one of the initial commissioners of the Kensington Screw Dock, and also from a New Bedford whaling house.
Deed AM 51, 570 (1834) shows William R. Rodman purchasing “all the machinery, engines, screws, fixtures, apparatus, tools, utensils, & implements, to the said oil factory, & screw dock, with other buildings and improvements.”
Rodman, was a merchant in New Bedford, MA.—then the whaling capital of America—and a member of a prominent New Bedford family with whaling interests. Rodman’s mansion survives in New Bedford.
Rodman had Kensington shipbuilder Samuel Bowers—an earlier owner of this site—convert the “Rebecca Sims,” a famed ship originally built by Bowers, into a whaling ship.
Deed GWC, 50, 160 (April 7, 1850) shows Rodman sold the property for $30,000 to Edward Rowley, Algernon Ashburner, and George B. Keen, trading as “Rowley, Ashburner, & Co.,” later “Rowley, Ashburner, & Co., Kensington Screw Dock.”
Marble & Co. not only misidentifies Rowley, Ashburner, & Co. as shipbuilders, but also states they were the original owners and operators of the Screw Dock (page 54, 1BII Report), when in fact they were commission merchants, who had been supplied over the years by the products of the Spermaceti Works and then bought the place in 1850. The forming of their partnership and the fact that they are commission merchants is mentioned in a newspaper advertisement of 1843:
“Co-Partnership Notice. Edward H. Rowley and Algernon E. Ashburner have this day entered into a copartnership under the firm of Rowley & Ashburner, for the transaction of a general commission business, at No. 6 South Wharves. Edward H. Rowley, Algernon E. Ashburer, Phila. January 2, 1843.” 
- The New Bedford Mercury, (Dec. 13, 1833)
- Baltimore [MD] Gazette and Daily Advertiser (Dec. 26th, 1833)
- The North American and Daily Advertiser (Philadelphia, PA), January 6, 1843