Editor's note: Kenney did not release a policy paper on Friday, Oct. 9, 2015, as his campaign had said he would. His campaign said the paper would likely be released the following week.

One of the most reliable aspects of Jim Kenney's mayoral campaign has been the candidate's enthusiasm for the Port of Philadelphia — and its expansion.

Now, his campaign is expected Friday to call on the Philadelphia Regional Port Authority to devise a plan for that expansion, which the former councilman has touted as a way to create as many as 10,000 new blue-collar jobs in the decade ahead.

Kenney, a South Philly native and former board member of the Philadelphia Regional Port Authority, has said Philadelphia is poised to triple its container traffic based on a number of local and international factors.

"The Panama Canal expansion is coming online in 2017. There's stories about more congestion issues at the Port of New York and New Jersey," said Kenney's policy director Jim Engler. "Other ports are taking advantage of this and Philadelphia also needs to be in line for that."

After decades of relatively stagnant container volume, Philadelphia's port saw a big increase in imports each of the last two years. The Philadelphia Regional Port Authority, a state agency that leases the piers and terminals to private operators, released figures showing 2014 was the best year for container traffic in the city's history.

But will the strong volume continue? And will it grow by the leaps and bounds needed to support Kenney's notion of thousands of new jobs?

Over the last 20 years, yearly traffic has averaged around 210,000 TEUs, with a TEU (twenty-foot equivalent unit) being an industry standard for measuring the volume of shipping containers. As recently as 2012, the number of TEUs at Philly's port had dipped from the previous year.

Despite the last two years' growth, Philly is still the 25th largest North American port, ranked between Anchorage, Alaska and Halifax, Canada.

Brookings Institution fellow Adie Tomer, who studies freight and infrastructure, said Philly was not alone in seeing a recent uptick in container traffic.

"Most of the East Coast ports did really well because of labor disputes on the West Coast, but that was an isolated event," said Tomer. That major dispute, he added, was resolved in February.

Tomer also cautioned that Philly was not alone on the East Coast in revving up large and often similar expansion plans, with an eye to capitalize on new traffic from the Panama Canal widening, due to finish in April 2016.

"There's a veritable arms race going on between these East Coast ports. It can be hard to compare them, but the investments in ports are occurring faster than the growth in global trade, and there will winners and losers," he said. "The bigger story is that Philly needs to be really confident if it makes this investment that it can outclass other East Coast ports that are making the same investments."

In 2004, the port counted 178,000 TEUs, while last year, the PRPA tracked 449,000 TEUs. The Packer Marine Terminal, which is Philadelphia's largest port terminal, has an annual capacity of around 450,000 TEUs.

Engler also noted that leadership turnover was coming to the PRPA, with a new board and the replacement of 20-year executive director James McDermott. Sources have said that shippers and terminal operators had long butted heads with the organization.

One such terminal operator, Holt Logistics, agreed that it was ready to expand, with notes from two private shipping lines affirming their commitment to bring more cargo to Philadelphia.

"We've doubled our volume over 10 years, and we can double it again," said Kevin Feeley, a spokesman for the family that owns Holt Logistics, which also has terminals in Gloucester and Paulsboro, N.J.

Kenney has mentioned his support for the Holts' plans for two big container terminal expansion projects that together could increase Philadelphia's annual container capacity to 1.55 million TEUs. The Holt family, brothers Mike, Leo and Thomas Jr., have donated $6,200 to the Democratic candidate's campaign over the last year.

If that added capacity were actually filled — and assuming other large ports didn't increase — it would make Philadelphia the 12th largest port in North America.

Tomer said the presence of several massive, local refineries is probably Philadelphia's most appealing draw. But there is a lot of local disagreement over how much of the nearly 200 acres of empty land south of the Packer Terminal, known as Southport, should be dedicated to energy.

Philadelphia Energy Solutions, which runs a South Philadelphia refinery, is pushing for a focus on refining and hydrocarbon processing, while the Teamsters union has said it wants more automobile-processing. Kenney, along with many longshoreman and Holt, has pushed for container cranes and storage space, saying the other uses require far fewer laborers.

Perhaps the greatest testament to the actual demand for more port space is that, despite 15 years of calls to expand, the Southport land is still mostly undeveloped.

Peter Leach, editor-at-large of the Journal of Commerce, who has followed the project for years, agreed Philly had many natural strengths and the potential for growth but that the project had largely been stymied by "politics."

"For a city that's been deindustrialized, container ports offer one of the only opportunities for blue-collar employment," he said. "But there's something about Philly that prevents things from getting done quickly. They talk projects to death."

One reason for infighting might be that any expansion will likely entail large state subsidies. A recent City Controller's report, which enthusiastically argued for port expansion at Southport, said the project would like cost upwards of $500 million.

Gov. Wolf's office said it was committed to the project and had already launched an "economic-impact study" for Southport.

Story correction: The Holt family has given $6,200 to the Kenney campaign in the last year. The story originally reported the donation total as $9,700, using figures from the online database of the Philadelphia Records Department. The database duplicates contributions that appear on both initial campaign finance filings and amended filings from candidates.