December 26, 2008

A Look Back at the San Leandro Marina Boat Harbor

The January 1964 edition of The American City published an article by San Leandro Public Works Director G. Homer Hamlin about the recently constructed San Leandro Marina. The article mentions plans for a future recreation center and an expectation that the facility will begin paying its own way.

Here is the article in its entirety:

Drawing of San Leandro Marina in 1964

More Than Just a Marina
Public Works Director
San Leandro, Calif.

Ask anyone around San Leandro, Calif., and he will tell you that our new bayside facility is more than just a marina. It already includes 308 berths, a golf course, parking lots, restrooms, play areas and a children's fishing pier. The future will bring to this waterfront playground a restaurant, a boatel motel, 200 more berths and a recreation center building.

In design, too, it rises above. the class of simple marinas. We carved this new facility out of the tidal flats of San Francisco Bay by dredging and clamshelling the submerged material to produce solid banks and a deep channel connection. Buoyant concrete piers with hollow interiors near the gas pumps provide adequate fire resistance. Wood and styrofoam comprise the other docks, with extra support where ramps with their concentrated loads seek to bury them underwater.

An accurate feasibility report provides the essential backbone for marina construction. A good one will accurately forecast whether the proposed marina will pay for itself or whether it will turn into a money-grabbing monster that siphons off tax revenue. We have spent about $1,100,000 on our marina thus far, no small amount for a community of 66,000 residents. In March it will celebrate its first anniversary. Judging by rentals to date we should hit the first-year goal of 150 rented stalls as estimated in the report. This would fill about one-half of those already constructed.

Bigger Boats
Now that our marina has taken shape, the boats here seem to be getting longer. Many local owners have now made the transition from trailer-borne craft to larger ones that need permanent berthing. They probably tired of the two-hour task of washing the salt water off the trailers and repacking wheel bearings after every outing. And even though the boat-launching ramp is convenient and free (except on holidays and week-ends when we levy a one-dollar charge), launching and recovery can become tiresome and time-consuming. Permanent marina berths give boat lovers good reason to switch to bigger boats which they can leave in the water under protective eyes.

At 65 cents per lineal foot per month, slip rental here is not excessive. An annual rate equal to ten month's rent is also available. No vessel can occupy a berth shorter than itself. Monthly rates vary from $13.65 for a 21-footer up to $31.20 for a 48-foot craft. If boats occupied all 308 stalls, we would realize about $5,400 monthly from these fees alone. Berth rental now comprises a major source of revenue. As concessions go up, however, they will furnish the lion's share. The future will find slip rental and fuel sales each contributing about one-fifth of the total revenue.

These planned concessions, will include a restaurant, a snack bar, repair and sales sites, a motel, club facilities and some others. An approved concessionaire will lease a designated area from the city and construct all improvements at his own expense. Leases will run from 20 to 50 years, depending on the value of the improvement. Rental fees will include a percentage of gross income with a specified minimum amount: Several prospective concessionaires are now consulting with us about these leases.

Strong Decks
Our wooden piers are stronger than those of most marinas because the top decking runs perpendicular to the length rather than diagonally. For years designers have placed decking at an acute angle. This actually creates vertical planes of weakness parallel to the grain. By placing our decking at right angles to the stringers we develop much more strength in torsion. This design saves money because it eliminates excess cutting and wasted triangular sections. All exposed lumber is construction-grade Douglas Fir, penta-treated with heavy-retention solution according to Specification C-18-61 of the American Wood Preservative Association. Piles and other hidden lumber got the more economical creosote pressure treatment.

A typical pier begins at the dike with a ramp about 80 feet long. The anchored end rests on a concrete abutment but it is free to rotate vertically with the tides that sometimes change the elevation as much as ten feet. About half way out, a galvanized steel gate firmly bars the way. Only those with boats moored at this dock own keys. The other end of the ramp rides on a small pair of wheels that travel in steel channels on the floating pier as it rises and falls. A ribbed steel plate provides the transition from ramp to pier. We are experimenting with some Minnesota Mining and Manufacturing Safety Tread to obtain more traction on these steep plates.

Main-pier lengths vary according to the number and size of berths. The pier itself consists of a deck, six feet wide, supported by three longitudinal planks of Dow Chemical's styrofoam. Two-by-eight-inch stringers raise the deck above the styrofoam and hold it well above the water level. Angle-driven wooden dowels firmly fasten longitudinal foam planks to the hollow deck section. Steel loops loosely encircle the piles adjacent to these piers to allow tidal movement.

Finger-pier construction is similar but these piers measure only half as wIde. Here, too, decking consists of two-by-sixes perpendicular to the stringers. Fillets strengthen the connections where these finger piers join the main piers. Each joint contains one fresh water hose bib and two 15-amp, 115-volt outlets. All pier lights shine downward at an angle rather than parallel to the water where they could blind boat operators. These are Shalda #583 fixtures with 100-amp lamps spaced 18 to 34 feet apart.

Because it floats, gasoline poses a terrible fire hazard on water. Our four pumps each dispense a different fuel: regular, ethyl, an oil-gas mixture and diesel fuel. Because all are so dangerous we chose lightweight, hollow-concrete sections for those piers near the pumps. Manufactured by the Unifloat Marine Structures Corp. of Petaluma, Calif., they cost more than their wooden counterparts but they contribute a tremendous safety factor.

These thin-walled floats measure 8 feet long, 6 feet wide and 26 inches deep. Three-fourths submerged, they will sustain a live load of 40 pounds per square foot. Fir two-by-eights along the top edge hold them together and minimize the danger of collision-generated sparks. Attractive plastic bumpers set closer together here than on the other piers also help. A two-inch pipe with hydrants at 100-foot intervals supplies fire protection on the piers. Hoses provide the needed flexibility at pier joints. Several Greenberg all-brass wharf hydrants on 'the dikes supply an extra safety. factor.

The dikes that enclose and protect the marina basin required 200-foot-wide tops to accommodate all our planned facilities. Dredging the six-foot channel and the deeper marina basin brought up more than enough material to build them. The combined job, however, cost more than $500,000. First the contractor clamshelled the silty material into two parallel dikes which are 200 feet apart.

He then filled the intervening area with dredged and clamshelled material. We specified side slopes of five-to-one or steeper, but the silt surprised us pleasantly when it stood at three-to-one. Riprap then followed on these portions subject to erosion.

Utilities on Fill
With some trepidation we prepared to install utilities and streets on this unconsolidated fill. A liberal bed of pea gravel went in the trench bottoms to support the vitrified-clay sewer pipe. And we specified plastic gasket joints that can move somewhat without leaking. A small lift station holds the sewer depth to less than ten feet. This is nothing more than five-foot-diameter concrete pipes on end with two four-inch Wemco submersible pumps. With their small impeller clearance, the Wemcos at our sewage plant resist clogging so we chose the same type for the lift station.

Building the roads constituted another problem. The bad soft spots we tackled first by sheepsfooting dry clay into them:. Some of these measured 50 feet long. Then we sheepsfooted the lime-rock base material into this silt instead of adding it on top. This ½-inch material stiffened up to form a base eight inches deep with a stabilometer value of 65R. Next followed six inches of base material with a value of 78R. A 1 ½-inch hot-mix leveling course now provides a temporary surface. After full settlement takes place a paver will add another 1 ½ inches. Adjacent parking areas consist of a shot of asphalt applied directly on the base course.

A piled timber dock that bulges out from the dike bears the boat hoist near the basin entrance. The timber dock abuts the six-foot channel and provides a stable and clean area in which to work. The hoist itself is a Checo Tram Chief with Yale motor. Its two-ton capacity adequately lifts outboard motors and entire sailboats onto the timber trestle.

The adjacent nine-hole golf course, opened only a few months ago, has proved immensely popular. This, too, will double in size as need dictates. Some experiments at our activated-sludge sewage plant have solved the grass-growing problems on our fairways. Mixed with the existing soils, the sludge improves drainage and enriches the seed bed.

Our young marina is attracting residents at a furious rate. Every day more turn up to watch and then take part in the activities there. Soon, this facility will begin paying its own way and much of it will be due to the extra thought that makes this community attraction more than just an ordinary marina.

Posted by Mike Katz-Lacabe at December 26, 2008 1:52 PM | TrackBack
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