Jack, Here is the photo I promised you. It is a Tactical Data Network (TDN) Gateway mock-up. It has 1/16 the capability of the real system at 3% of the cost. I used many different vendors to include ISC. I went with ISC because I could get a lot of the items I needed at one stop and the price was very competitive. The quality of the products is superb, and I would use ISC again for further applications.
Thanks again.
GySgt Ross “H-Bomb” Hrynewych
US Marine Corps, EMTC Instructor
Publisher’s Note: The photo to the below shows the completed system. Components supplied by ISC include the PTRK cabinet, rackmount powerstrip, blank panels, UPS, utility drawers, 10-32 rack screws, and cable management (in the future).
Information Support Concepts (ISC) has discontinued the monthly product special. Since we are now running weekly specials with much deeper discounts, it made sense for the monthly special to be replaced. We will now have a featured product each month, and direct our customers back to the weekly special for discounted items.
You can click on this link to see the current weekly product special!
This month we will highlight the value of lacer bars. Lacer bars are a type of cable management, and give you a place to tie off cables or wires. Click here!:
http://www.iscdfw.com/onlinecatalog/racks/rack-accy/cable/horz-lace-bar.htm
In the application pictured above, the Marines need some lacer bars to complete the configuration. They are going to determine the style and amount of offset needed, and then place an order.
As always, ISC personnel are ready to answer your questions, and can confirm what product will work for your specific application. If you have a question, just call us at 800-458-6255.
Flat Lacer Bar without Offset
Round Lacer Bars with Offset
“L” Shaped Slotted Lacer Bars with Offset
Temperature’s Rising. . . Or Not?
January 11, 2008 • Vol.30 Issue 2
Spurred by rising energy costs, many enterprises have considered raising the baseline temperature, or set point, inside their data centers. While there’s no denying that thermostat settings can impact equipment performance, deciding just what a set point should be is hardly a straightforward issue.
“The temperature setting is important to IT equipment performance, which is why manufacturers have temperature ranges specified for their equipment,” says consultant Don Beaty, president of DLB Associates and former chair of the technical committee on mission-critical facilities, technology spaces, and electronic equipment of ASHRAE. “The temperature setting also impacts the performance of the cooling plant. The optimum ranges do not quite mesh, but over a period of several years, IT manufacturers, facilities engineers, and operations personnel worked together to develop a set of thermal guidelines that would allow for both acceptable IT equipment performance and reasonably low energy consumption of the cooling plant.”
The culmination of this effort, he notes, is an ASHRAE publication titled “Thermal Guidelines for Data Processing Environments,” published in 2004.
ASHRAE Guidelines
Beaty states that based on these guidelines, data centers should be able to operate “in complete safety” at a range of 68 to 77 degrees Fahrenheit. He believes most data center set points do not reach the latter number in part because it is difficult to achieve uniform temperature distribution throughout the facility. Measuring a range of 10 degrees or more between the inlet of one server and another—for example, 68 F at the bottom of a rack and 78 F at the top of a rack—is not unusual, Beaty notes. “If facilities could solve the uniformity problem, they would likely be able to work at the higher distribution temperatures and achieve significant energy savings,” he explains.
ASHRAE guidelines also recommend a maximum hourly rate of change for data center temperatures, pegging this point at no more than 9 degrees per hour. “High rates of change, or constant temperature cycling, can result in increased equipment failure rates,” Beaty says. Tape drives, in particular, are susceptible to large changes in temperature or relative humidity, he notes.
However, others argue that the higher the set point, the shorter the window of opportunity to address cooling failures. A study by Opengate Data Systems found that a typical data center running at 5kW per server cabinet will experience a thermal shutdown within three minutes during a power outage. Higher density cabinets with 10kW will shut down in less than a minute. “Thermal runaways can wreak havoc on a data center, causing instant data loss,” notes a spokesperson for Active Power, a manufacturer of UPS flywheel systems.
Meanwhile, Mark Monroe, director of sustainable computing at Sun Microsystems says companies can achieve an energy cost savings of 4% for every degree of upward change in a data center’s set point. In a recently conducted study of 14 of Sun’s data centers, Monroe discovered that eight facilities had the temperature set at 68 F, five at 72 F, and one at 74 F.
“If you’re running at 68 degrees, you’re running at the bottom level of most of those ranges,” he notes. “There’s no reason why you can’t move to 78. This is a really simple thing to do.”
Beaty agrees with Monroe, but not entirely. He claims raising a data center’s set point can have a significant effect on energy usage, “but there is no set percentage reduction in energy cost that can be stated based on, say, a 1 degree Fahrenheit rise in temperature.” What can be said, he reports, “is that chiller efficiency will increase, and assuming that economizers have been installed, there will be a significant increase in the number of hours per year that the economizers can be used. This increase is specific to the type of economizer (water-side, air-side, or evaporative) and the ambient temperature distribution of each site.
Several companies have introduced products aimed at safely raising set points. Examples of such products include Dynamic Smart Cooling from HP and AdaptivCool from Degree Controls.
Humidity Levels Warrant Attention
When addressing the issue of data center thermostat settings, storage administrators should also consider the impact of higher temperatures on data center humidity. Excess humidity can cause condensation to form on electronic components, leading to wasted cooling and, in turn, a higher energy bill. Insufficient humidity can result in ESD (electrostatic discharges), which can cause equipment to shut down and, quite possibly, sustain damage in the process.
In data center environments, humidity is traditionally measured as “relative.” Relative humidity is expressed as a percentage and measures the amount of water in the air at a given temperature compared to the maximum amount of water that air can hold. According to Beaty, an ASHRAE technical committee that focuses on computer rooms recommends that relative humidity be kept in the 40% to 55% range.
Some experts believe keeping humidity at the low end of the range cited by Beaty won’t necessarily eliminate ESDs. “You can be fine in your moisture range and still have an ESD event,” says Coy Stine, a simulation engineer at Degree Controls.
Beaty advises storage administrators to carefully evaluate the pros and cons of keeping data center humidity levels low. “The lower limit . . . should probably be set based on a total cost of ownership analysis,” he says. He believes the best course of action entails weighing the operating cost of humidification against the cost of increased equipment failure due to a lower relative humidity limit.
by Julie Ritzer Ross
Don’t put your hardware in danger!
Call the Rackmount Ranger!
800-458-6255.
The “Follow Me” Truck
On another of the infamous T-38 (see photo below) solo out-and-back missions, a flight of ten student pilots were enroute from Willie (near Phoenix) to Holloman Air Force Base in Alamogordo, NM. This would have been a fairly uneventful mission, were it not for the fact there was a foreign student involved. If you have read my previous story about the Indonesian student trying to get to Vandenberg Air Force Base (see last month’s newsletter), you can skip the next paragraph.
Foreign students were officers from friendly nations who came to the US to learn how to fly. After completing pilot training they would normally go back to their country of origin to be trained in the particular aircraft in their nations’ inventory. Sometimes there was advanced training in the US, but mostly they just went through “undergraduate” pilot training, meaning T-37 and T-38. At the time I was serving as a T-38 instructor, we trained Danes, Norwegians, Indonesians, Saudi Arabians, Iranians, Nigerians, and many others. The US trained so many Germans they designated a single Air Force Base as the home of that operation.
On this particular mission, there was a Nigerian student named Lieutenant Matt Osume. Matt was a decent pilot and did pretty well in pilot training. However, he was not that familiar with the day-to-day operations on an Air Force Base, or perhaps he was just not very observant.
There are a lot of different vehicles operating around a base. At our home base of Willie, they had a tram that you got on to ride out to your airplane. There were more than 80 aircraft on the flight line, and those closest to our squadron building were right outside the door. However, the other end of the flight line was about ½ a mile away, and to ensure everyone got to their airplanes as expeditiously as possible, we had a tram. This tram was pulled by a little tractor like vehicle, and usually had two cars. If you have ever been to Disneyland and ridden the tram from the parking lot (many years ago), or the parking garage (most recently) the trams in both cases are very similar.
Another vehicle you frequently see on an Air Force Base is the “follow me” truck. This is usually a pick up truck, and it is so named because there is a big sign in the bed of the truck with flashing lights around it that reads “follow me.” This truck is operated by the transient support people, who are the ones that work with visiting aircraft. When a visiting aircraft arrives at the base, it is usually met by the follow me truck at the end of the runway. The aircraft is inspected by the transient ground crew, the landing gear pins are installed, and then the aircraft follows the truck to the Base Operations (base ops) building where it is parked. The crew then shuts down the engines, and goes into base ops. If they are not staying, the aircraft is refueled while they are inside base ops getting an update on the weather and planning the next leg of their mission.
Another vehicle is the sweeper truck (see photo below). This vehicle looks just like the one you might see once in a while in your neighborhood. It has the rotating brushes and the big vacuum cleaner. Its purpose on an Air Force Base is to constantly patrol the taxiways and runways (when they are not active, or in periods where no aircraft arrivals or departures are anticipated). They are the primary weapon against FOD (Foreign Object Damage). Since we are talking about foreign students, I need to clarify a little bit. FOD is not property that belongs to foreign students. In this case the F in FOD applies to objects that are foreign to jet engines. Things like rocks, pencils, paper, nuts/bolts/washers/screws, or any other small object that could be ingested by the aircraft engines as the aircraft moves over or adjacent to them. FOD damage to aircraft engines causes millions of dollars in losses each year. So bases work very hard to ensure that there is no FOD where aircraft are present. To supplement the sweepers, there are often “parties” of pilots and ground crew walking around the ramp to pick up FOD.
Now you would not imagine that anyone could confuse a follow me truck and a sweeper. The truck has the big sign, and of course it is really a truck, which does not look anything like the sweeper vehicle. However this is exactly what happened.
At Holloman, all the T-38s were landing at about five minute intervals. Since there are usually only two or three follow me trucks at any Air Force Base, this quickly maxed out the trucks. As soon as they brought one aircraft in to base ops, they had to drive out to retrieve another one. Sometimes it took a while for the follow me truck to reach the aircraft. The number of planes arriving was exacerbated by the layout of the runways at Holloman.
Holloman has three runways, none shorter that 10,000 feet, and the two crossing runways (crossing at a 90 degree angle (runway 07/25 and runway 16/34)) are both longer than 12,000 feet. The third runway (04/22) crosses the X made by the other two at the 07-16 points, so the layout almost looks like the roman numeral ten with only the top crossbar. The taxiway system to support this layout is enormous. Taxiing around Holloman can make you feel like you are in the middle of nowhere, especially when out beyond runway 04/22 (about 4 or 5 driving miles from base ops).
Lt. Osume landed safely and taxied off the runway. Not being in site of any buildings at the base, he started down the taxiway looking for the follow me truck.
At this time of day, near sunset, the only other vehicle in sight was a sweeper, so Lt. Osume, evidently unable to distinguish it from the standard blue Air Force pick up truck, started following it. Since the sweeper was pursuing his regular route, and not trying to go back to base ops, Lt. Osume was led on a merry chase around the taxiways at Holloman. Evidently the sweeper did not know he was being followed. This would be bad enough except that another T-38 was taxiing in, headed in the opposite direction (head-on) with the sweeper.
Once the sweeper realized he was in the way of an aircraft, he was going to turn around and get out of the way. Once he turned around he found another T-38 behind him. At this point, the sweeper turned off his vacuum and brushes and moved off the paved taxiway into the desert. He had effectively gotten out of the way, but there were still two T-38s pointed at each other, with no way to turn around on the narrow taxiway.
It was fortunate that the other T-38 was being flown by a more experienced student. As I recall it was Capt. Bass. He and Lt. Osume were on the same ground control radio frequency, so they started talking to each other. Capt. Bass told Lt. Osume to taxi slowly and carefully over to the right edge of the taxiway, while he provided feedback on where Lt. Osume’s right wheel was (since you can’t see your own wheels from the cockpit). Lt. Osume got over as far as he could. Then Capt. Bass slowly and carefully moved over as far as he could to the right, with Lt. Osume providing feedback on the position of his wheel relative to the edge of the taxiway. Once this was accomplished, it looked like they had enough room for the aircraft to pass (the T-38 has a wingspan of about 25 feet). So with Lt. Osume giving feedback, Capt. Bass taxied by him with a couple feet of wingtip clearance.
While all of this was going on, the other aircraft had all made it to base ops, and the follow me trucks could now go out and pick up the stragglers. Each aircraft was able to make it in to base ops with no further problems.
I think the person who suffered the most in this whole episode was the poor sweeper driver. I doubt if any other aircraft had ever started following him around the base, or had him penned in on a taxiway. It must have been a frightening experience for him.
Thanks for reading, and I hope you enjoyed this month’s newsletter.
Please direct your comments to Jack Burlin.
