Deep Ports Research Articles

The local impact of containerization

We investigate how containerization impacts local economic activity. Containerization is premised on a simple insight: packaging goods for waterborne trade into a standardized container makes them dramatically cheaper to move. We use a novel cost-shifter instrument -- port depth pre-containerization -- to contend with the non-random adoption of containerization by ports. Container ships sit much deeper in the water than their predecessors, making initially deep ports cheaper to containerize. Consistent with New Economic Geography models, we find that counties near container ports grow an additional 70 percent from 1950 to 2010. Gains predominate in counties with initially low population density and manufacturing.

The Local Impact of Containerization

We investigate how containerization impacts local economic activity. Containerization is premised on a simple insight: packaging goods for waterborne trade into a standardized container makes them dramatically cheaper to move. We use a novel cost-shifter instrument -- port depth pre-containerization -- to contend with the non-random adoption of containerization by ports. Container ships sit much deeper in the water than their predecessors, making initially deep ports cheaper to containerize. Consistent with New Economic Geography models, we find that counties near container ports grow an additional 70 percent from 1950 to 2010. Gains predominate in counties with initially low population density and manufacturing.

Rivers and ports in transport history of Cameroon, 1916-1961

In direct contrast to Europe, Asia and North America, Africa has very few navigable rivers. This paper focuses on the preponderant role played by water transport in the form of rivers and ports during the colonial period. Although not blessed with much navigable rivers and natural deep ports, the Colonial administration as well as the population of Cameroon depended so much on rivers and ports for their physical mobility, transportation of bulky goods, mails migration and above all European consumer goods which came in from Europe and were head loaded into the hinterlands. Therefore rivers and ports played economic, social and political roles. Despite these important roles, the place of rivers and ports has been relegated to footnotes in historical narratives of Cameroon. This paper therefore, aims at lifting rivers and ports from the footnotes of Cameroon history into the text. It confronts the importance of such a technological system to both the colonial administration and the indigenous population. What were the type of goods that were transported via rivers and ports? More crucial to the essay is the importance of the ports in the development of the cities and the migration of people into areas where ports were found. In what ways do we linked the ports and rivers to the global mobility of goods and modernity?

Acoustical oscillation in a combustion system with a flat flame

Self-excited acoustic oscillations in a laboratory combustion system containing a premixed flat flame are investigated. The flat flame is stabilized by a copper matrix burner with about 700 deep ports and burns in a resonator tube (diameter 30 nm) of the same area. The system may therefore be treated one-dimensionally. The perturbing mechanisms under consideration are the oscillating reactant input and the oscillating heat transport from the flame to the burner matrix due to the particle displacement (which can be derived by integrating the particle velocity of the standing soundwave). No oscillations are found if the velocity of the reactants is equal to or larger than the laminar flame speed. The experiments show an instability range in the plane of equivalence ratio φ and oscillation period T similar to other studies using premixed gas-fired rocket chambers. However, in our system there is a definite limit with a minimum oscillation period of 1.2 ms; no oscillations with smaller periods are found. Acoustic measurement of the burner impedance shows a change of sign (±) of the reactance (imaginary part of impedance) exactly at this limiting oscillation period. By analogy to electric line theory an “inductive” and a “capacitive” burner reactance can be defined. Oscillations were only observed at an inductive burner reactance. Under the acoustical condition the heat (or temperature) oscillation is exactly in phase with the pressure oscillation if there is a negligible combustion time lag. The criterion set up by Rayleigh is fulfilled.

Operating experience gained with flat hydraulic gates under winter conditions

The fiat gate is the basic type employed to close the ports of water passages in domestic hydraulic structures. Owing to their technological nature, economic setting in the structure, and ease of installation, operation, and repair, flat gates of various design modifications are universally employed in deep and surface ports of considerable size over a broad range of working pressures. They have been the subject of considerable study and are quite reliable in operation. At some hydrofacilities, however, there have been instances of damaged flat gates. Analysis of the causes of these damages has yielded voluminous data, on the basis of which design standards have been rendered more precise, and rules governing the fabrication, installation, and operation of the equipment are upgraded. A few characteristic cases of damages incurred by fiat gates in the post-war period with a description of accompanying instances and an analysis of the causes are examined below.* During a temporary period of operation in March 1952 at one of the concrete spillway dams on the Svir' River, an emergency situation arose with a flat wheeled gate covering an opening of 27 m and designed for a head of 6.6 m. The gate was designed in accordance with technical specifications and norms issued in 1935, and was constructed by welding grade St. 3 steel with type E42 electrodes (TsM-7 coating). The mechanical properties and chemical composition of the steel met standard requirements. For three months prior to the emergency, the gate was set into the grooves of the repair gate and operated under a head of 6.0-6.5 m; at the time of the emergency the effective head was 5.72 m. For one weak prior to the emergency, a severe cold spell settled over the construction region, and nighttime temperature dropped to -30"C; at the time of the emergency the air temperature was- 22"C.

Organ-Pipe Oscillations in a Burner with Deep Ports

Data are presented on acoustic oscillations produced by a burner using a hexagonal bank of hypodermic tubes as deep ports. Most of the tests were made with ethane as the fuel, but some tests were run with methane and propane, for comparison. Both the diameter and length of the combustion chamber were varied. It was found that the combustion chamber could be considered as a driver which forced the slugs of gas in the ports to oscillate. Burning of the incremental pulses of combustible mixture periodically issuing from the ports furnished energy to drive the oscillations when the pulses burned in phase with the oscillating component of the pressure in the chamber. The phasing depended on a time-lag factor which was a function of the velocity of the gases through a space, similar to dark space, between the burner ports and the mean burning points, and the width of the space itself. The oscillations not only ceased when there was a failure to satisfy the timing criterion, but also ceased upon approach to either rich or lean blowoff limits of the conventional type. This premature cessation apparently results from the flame burning from fewer ports as the limits are approached, less driving energy being available.