About three years ago we acquired this former GATX tankcar 23799, built in 1920 with a capacity of 8,000 gallons. The frame and trucks are long gone, the tank itself having been repurposed to hold diesel fuel for the east end yard office at the P&LE's Gateway Yard. We plan to use it as a feedwater storage tank for the J&L Narrow Gauge, however the presence of residue diesel fuel presents a bit of a dilemma.

The hatch opening is too small for me to enter, and I would not feel safe letting anyone into the tank. So cleaning it would have to be done from the exterior. I am looking at several options including steam cleaning, pressure washing, solvents etc. Then I stumbled upon the concept of microbial remediation. Basically, oil eating microbes can be introduced into the water in the tank and with time and agitation the microbes will eat the oil, getting the amount of residue down to the point where carbon block filters can take care of the rest.

I will be adding two small access points near each end of the tank to aid in post microbe pressure washing and to facilitate the installation of magnesium anodes. These will probably be heavy plate burnouts welded into a hole in the tank with bolted covers. From these access points the interior of the tank can be reached with a pressure washer for occasional removal of algae and other contaminants from the tank.

Once the water system is complete, we will be able to retrieve water from a small stream, pump it down to the tank, filter it, store it and then final filter before going into the saddle tank. By controlling water quality and ph it should go a long way toward boiler preservation.

This microbe treatment sounds very interesting, but if the tank held diesel previously, I'm curious how you are going to safely cut holes in the ends without the tank catching on fire?

Also, is there much harm in simply mixing the water with the residual diesel fuel for boiler use? Wasn't a common preservation method for boilers to coat the inside of the boiler with diesel for dry storage?

Eric

I will be doing the remediation before we cut any holes. Yes there is a danger of a vapor explosion otherwise.

Excessive oil in a boiler causes foaming.

The common way to prevent a fire or explosion when working on a tank is to fill it with an inert gas... the easiest way to do that is to put dry ice (usually pellets) in the tank. There is a formula for the amount of dry ice needed per gallon.

Good idea Randy. I figured there had to be an easy way.

My only experience with microbes and a oil tank was when I had to replace my home heating fuel oil tank account of microbes eating through the steel of the oil tank and caused it to leak.

I was charge of multiple petroleum storage facilities for over ten years, so I can speak to this. Obviously a confined entry requirement if anyone breaches a opening, even sticking a hand in. My workers would occcasionally do permit required confined entry, But in this case, I would contract with a tank cleaning service. There is an excellent , cost effective service close to you in Punxsutawney, Pa who would do it withou your folks getting themselves in trouble. Just my 2 cents, your mileage may vary

The Santa Fe used to fill boilers with fuel oil if they were going to be laid up for awhile, as a rust preventive measure. They said they would foam for a few days after being put back in service, then all was well...

Also, you can use gas or diesel engine exhaust to displace air in the tank, to prevent it from exploding when you torch out your access holes.

I'm more concerned about the use of stream water in the locomotive than the oil in the tank (if you can't drink it don't put it in a boiler), and the potential of microbes that eat oil potentially creating problems in lubrication. I think farming the cleaning out to the licensed and insured pros makes a lot of sense considering potential liability, have done so in the past with good result for a similar situation but the car was still on trucks. Sammy's advice is good about very small amounts of residue if the tank is essentially empty. You may be overthinking..... if you do get a bit of foam for a while, you won't stab the limited at the junction out on the main line after all.

The microbes die out after they have consumed the oil, and certainly won't live through a winter nor would they survive a boiler. Stream water run through a sediment filter, a series of carbon block filters and a UV light is drinkable. The only step I am not taking is the UV light as we don't plan to actually drink this water.

The little bit of residual oil in the tank may not present much of a problem if left as is, but for a couple hundred bucks and a couple of months of time I can probably get half to 3/4 of the residuals removed. It is a low risk activity and I am curious to see just how well it will do. I'm not worried about liability as I am unlikely to sue myself.

A light coating of oil would help keep the tank from rusting. A freshly cleaned tank will rust and consume the oxygen in the tank. As you said don't let anybody go into the tank.

TSP That stuff cuts oil and other dirt like nothing else. Painters use it but I find more and more uses for it. It's "safe enough" to blast around on equipment but makes the grease/oil just run off like rain water.

T7

The tank would be a confined space that would need appropriate ventilation before anyone entered and while anyone worked inside.

I would install your water piping so that there can be NO possible ingestion by a human. I am thinking of biological or chemical nasties that might be in the stream you're using as a source.

The oil will float to the top anyway. Fill the tank and skim it off the top with oil absorbent materials, like floating socks and the like. Take the water from the bottom.

The bottom of actual diesel tanks, contaminated with water, can and do rust out. The water will quickly displace any petroleum residue down to bare metal.

If money were no object, I'd have someone come in and professionally clean, blast, and coat the inside of the tank, to prevent rusting.

If, for some reason, you decide that you or someone 'has' to enter the tank, a blower should be set up and run for several hours to change out the air, someone should be watching you from the outside, and you should have a harness and rope on, so your unconscious or dead body can be yanked out of the tank without anyone else going in. (this isn't a substitute for the correct training and equipment) (I'm sure you are at least passingly familiar with confined space training, but people die every year going into confined spaces).

I’m all for most DIY, but I’d at least give the pros a call to see what they’d charge. Travel and setup might be more than you want to invest, but you don’t know if you don’t ask.