• US Navy Rear Adm. James McManamon describes the benefits of Envelop covers to crew members aboard the guided missile destroyer USS McFaul. (supplied).
    US Navy Rear Adm. James McManamon describes the benefits of Envelop covers to crew members aboard the guided missile destroyer USS McFaul. (supplied).

Will the Navy standardise on Envelop Covers?

Contributed by Aussie Pumps Chief Engineer, John Hales.

Having spent a lot of time over the last 20 years with Naval Defence projects, we have worked with a wide range of both combatant and support vessels. Seeing our sleek new DDGs, our LHDs and the mighty HMAS Choules, we can’t help but think how surprising it is that these vessels have millions of dollars of topside assets that still don’t have Envelop covers.

Australian Pump introduced Envelop covers to the Australian Navy almost 15 years ago. The ANZACs were the first to get on board and now have something like 60 or 70 covers per ship. Other opportunities for asset protection on those same ships are still being identified.

The FFGs proved the point with the SPO moving quickly to ensure that all important assets, from the CIWS to 50 calibre machine gun pedestals, were protected from corrosion.

Envelop covers were developed by NAVSEA a little more than 20 years ago. Having produced a cover to help control and prevent corrosion on the USN fleet, they put it out to tender for a commercial operation to pick up the ball and start making this tremendously effective product to protect USN assets.

USN Rear Admiral James P. McManamon is famous for saying “The end result of the analysis concludes that defining the Envelop Protection Covers as required equipment for outfitting of surface ships and funding that procurement is a financially sound decision.”

“Additionally, the effectiveness of Envelop covers in preventing the intrusion of sand and other contaminants significantly improves operational readiness of topside equipment” he said.

Envelop covers are now mandatory on all USN warships and yet we are slow to move. It is not that we don’t understand the technology, the benefits or how the product works. It is more a matter of finance and of course ships’ crews, particularly officers, understanding just how much time and money can be saved. Increased readiness is a huge combat advantage.


Envelop covers are unique in their construction and are not cheap. However the cost, compared to the maintenance costs of the asset, makes them the bargain of the century!

How lucky are we Australians that the US State Department will allow this US Department of Defence developed product to be sold freely into our Navy applications!


Envelop covers mitigate corrosion by conditioning the atmosphere under the cover with a Vapour Corrosion Inhibitor (VCI), which forms an inert layer that halts electron transfers, thereby preventing oxidation.
In addition, the corrosion protection protects against moisture, sand, dirt, UV, airborne pollution, heat, cold, FOD impact, and wind.

Although we have made hundreds of presentations on the product and you would have to be blind not to see Envelop covers on existing warships, the message hasn’t got through to Canberra. Why the product isn’t mandatory on Australian ship assets is something we can only wonder at. Is it bureaucracy? A lack of understanding of the value of the service these covers provide, or an education issue? The purpose of this article is to provide a remedy to the last point.

It is not just combatant vessels that should use Envelop. Last time our staff was on board Choules, we saw not only the 3 or 4 applications we had been invited to measure but several more locations where Envelop could provide significant savings in maintenance and improved readiness.

The same comment applies to the DDGs and LHDs. These magnificent ships still aren’t properly fitted out with Envelop and nobody knows why. Maybe it wasn’t part of the original Navantia kit? That’s possible.

In the meantime, Australian Pump has been invited onboard those vessels to take measurements for some assets, but that work has not been followed through. Key assets are still exposed to the weather, or worse, protected by plastic covers that trap moisture underneath.

“We have got loads of information on this and have made available data to Defence about the value of this asset. Surely we proved it with the ANZACs, FFGs and even the Army’s M777 Howitzers! “said John Hales, Aussie Pumps’ Chief Engineer.

Working closely with the factory in the States, the feedback we get from their end is that the factory simply can’t keep up as the US Navy equips its new ships with Envelop covers from the very start. Let’s hope BAE will listen and start thinking about getting Envelop covers on the Type 26 so that when these ships are delivered, they come already equipped with the protection they deserve.

Further information, including a great movie produced by the ANZAC SPO, is readily available from the Australian Pump Industries website, along with samples of the product and application lists and benefit data.

Contact API’s Defence Division’s Andrea Chiplin for a free Envelop data pack.

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