Holdfast Training Services Trial Blog

Being positioned away from London clearly Brad and I will be unable to get to any of the evening Institution lectures to broaden our scope as Engineers prior to professional review. Enter USACE’s Officer Professional Development (OPD) programme to fill that gap. The current programme to gather Baltimore District’s 15 military members is quarterly meetings of a day and an annual 3 day trip. This year’s 3 day bender centred around the civil works programme within the Baltimore District, more specifically on the restoration and maintenance of the Chesapeake Bay. Below is a quick canter through the challenge presented to USACE:

However, before the learning, the programme started with a PFA and Howard had instructed us that it was ‘tradition’ to make sure the superpower was kept in check. So after a nervous start a Brit 1, 3 was achieved; we also managed to avoid embarrassment in the later ‘Ultimate Football’ game; end to end exhausting fun.

After round 1 didn’t go their way we had to play with this funny rugby ball

Chesapeake Bay

When America was colonised the Chesapeake Bay and surrounding area were some of the first places that the settlers put down roots due to the abundance of seafood in the bay and the favourable conditions for shipping of a sheltered deep harbour. As Richard indicated during our river and flooding day in Chatham however, the impacts of firstly the Royal Engineers and later USACE building dams and developing farmland have, alongside over fishing changed the landscape. Now Maryland state must ensure that the bay now supports the industries (shipping and fishing) that have grown up within it as well as be environmentally sustainable.

Shipping is one of Baltimore’s biggest industries as it has one of only 2 ports on the Eastern Seaboard that can receive ‘Super Panama Tankers’ which require a 50’ channel. This is as a result of dredging channels and, despite biting the hand that feeds it; Maryland state law presents some difficulties to the disposal of the dredged material. Dredged material can’t be dumped in the open water of the Chesapeake Bay and new islands can’t be created within the State’s waters. Additionally all the material in the habour is considered contaminated (with heavy metals etc) potentially causing water pollution when disturbed.

Being America clearly the numbers are big: 4.5 million cubic yards (the volume of 1.5 football stadiums) per year of sediment needs to be removed from the bay channels for maintenance alone. It is 180 miles from Baltimore Harbour to the mouth of the Chesapeake and the Atlantic Ocean where the first open water dumping ground would be; this would be expensive so they don’t do it. Instead the solution is land reclamation, either extending peninsulas or enlarging islands, and as the dredged material looked as if it had all the structural properties of a soggy blancmange the land is mainly used to build nature reserves and still isn’t cheap.

The scale of the Chesapeake Bay

The current main destination is Poplar Island, which over the last 20 years has taken approximately 100 million cubic yards at a cost of $1 billion, so $10 per cubic yard, or $50 million a year. The engineering is pretty simple; build berm from sand etc, put in loch gate to drain out water, pump dredged material (80% water, 20% solids), let it settle and drain the excess water. Of greater complexity are getting the water quality to the acceptable standard to drain into the Chesapeake Bay, introducing plant species to be beneficial for wildlife and hold the island together and the liability USACE will have for the island once completed.

They are planning on handing the National Parks Service (NPS) as a nature reserve. However, the maintenance of islands made from contaminated dredged material isn’t the NPS’s Mastermind special round choice and so USACE will still be responsible, and liable, for ensuring the island maintains its integrity. Clearly in the grand scheme of things with both parties being Government departments it is merely the department best positioned to deal with the issue being responsible which is best for the Nation and Government but that philosophy is muddied by departmental budgets and politics.

Other elements of note were the Conowingo Dam on the Susquehanna river is now ‘full’ of silt which is going to result in more being transported down stream and into the Bay. This is again an area of liability controversy as it was built by USACE, in 1926, but is now operated by Susquehanna Electric Company (SEC). Clearly neither want to accept liability and pay the exorbitant dredging costs, though ultimately SEC has the upper hand as if they don’t deal with it behind the dam then the problem will get passed on to USACE when the silt hits the bay. From an E&M perspective, more interesting than the silt was 1950’s style sign, below.

Also the rare forethought of the 1920’s designer who foresaw the increasing need for electricity and built space for an extra 4 turbines over the 7 installed at commissioning. The original 7 turbines produced 250 MW of power, in the 1960’s the remaining 4 were installed with equal power output giving the dam an output of 500MW.

The very 1950’s sign and the 1960’s turbines.