U.S. Interstate sytem developed for military as well as commerce

reply to post by totallackey

But I do know the following statement is false: The Eisenhower Interstate Highway System requires that one mile in every five must be straight. These straight sections are usable as airstrips in times of war or other emergencies.

False though it is, this "fact" has become a fixture of Internet Web sites with names such as "You Probably Didn't Know That ..." and "Weird Fact Heaven."

For a historian, even an unofficial one, who believes that a fact should be, by definition, factual, what is particularly frustrating is that everyone seems to know this "fact." People — including those whose eyes glaze over if I even mention Gen. Roy Stone1 or the vitally important statewide highway surveys of the mid-1930s2 — get a twinkle in their eye when I mention the Interstate Highway System. "Did you know," they say to me cheerily as I grit my teeth, "that one in every five miles ..."

www.fhwa.dot.gov...

The problem with the whole "Interstate as runway" issue is that runways have to go at least generally in the direction of the winds. The interstate system through most of the US doesn't. Add to that the fact that a two lane interstate wouldn't support the wingspan of any large aircraft (it would barely support the wingspan of most fighters).

A two lane interstate (which most of them are) is required to have two lanes that are a minimum of 12 feet wide, the outside shoulder should be a minimum of 10 feet, and the inside shoulder a minimum of 4 feet. So we're looking at 38 feet of roadway, plus dividing wall, plus lights.

The wingspan of an F-15 is 42 feet 8 inches (roughly), so we're already four feet over what the road requirements are. An F-16 would fit, but it would be within a few feet of under what the road requirements are. The F-22 is even bigger than the F-15 is, coming in at 44 feet 5 inches (roughly). We haven't even BEGUN to talk about large aircraft, such as the C-130 that would be required to support fighter ops on any roadway runway.

Now add in the fact that their landing gear isn't stressed to handle landing on the rough surface of a roadway (if you've ever been down I-10 or I-12 and a few others, you know exactly what I mean), then you have a problem coming up. Even if you were able to successfully manage to land on the roadway, you wouldn't get off again, because all the debris on the road would FOD out the engines (which is why Russia builds intake doors onto their aircraft).

No matter how you look at it, American aircraft aren't designed for rough field operations (and Interstate runways are rough fields).

Not much to do with signage, I take note of the bridging. For example I-85/185 near Fort Benning GA has bridges with extremely heavy and deep beams side by side the entire width of bridges. I believe these are built for military use. Ft Benning has armored division(s) with M-1 and Bradleys.

As I have traveled I have noticed similar bridges at major crossroads to Interstates, I beleive those to be designated military routes.

Maybe others have noticed these bridges built far heavier than the norm, most of the newer ones have the deep welded triangular beams nestled side by side or the older deep "I" beam style with beams all very close together almost like you'd see on rail bridges.

reply to post by Phoenix


They're stressed for tank transporters to cross. They usually try to travel by train, but you see M-1s out there on trucks occasionally. You see a lot of MRAPs and Bradleys as well on trucks. Not all military bases have the stressed bridges, but the ones around the armored divisions do. Tanks and roads make a horrible combination, between the weight and the tracks.

reply to post by Zaphod58


In the cold war era it seems very plausible to have had plans to deploy A/C to the interstate system. Roads in my vicinity are running much wider and smoother than I-10 with comprobably wide medians I'd estimate to be 150' plus in many areas. Certainly enough to operate C-130 from anyway.

As far as fod is concerned I doubt military would just land in and take chances but in war emergency way back then I'd say a unit might be ordered to dispersal and ground crewman would prep area, remove debris, obstructions and possibly mat down A/C parking in preparation for air operations.

In the days of Supersabres, Starfighters, Thunderchiefs and Phantoms I could see that happening.

Originally posted by Zaphod58
reply to post by Phoenix

 

They're stressed for tank transporters to cross. They usually try to travel by train, but you see M-1s out there on trucks occasionally. You see a lot of MRAPs and Bradleys as well on trucks. Not all military bases have the stressed bridges, but the ones around the armored divisions do. Tanks and roads make a horrible combination, between the weight and the tracks.

Roger that, I see these bridges far away from bases and a few bridge replacement projects done last ten years on major crossroads have gone in built this way.

I'm glad they at least think ahead if the military need arises but also see it in trepidation domestically nowadays lest it be misused.

Do they not teach this aspect of the Interstate Highway Act anymore in school? It is a well known and well documented understanding that it was for dual purpose....education these days I suppose.

reply to post by Phoenix


There was talk of using the interstate as emergency runways, but it never amounted to anything. It's not just the roadways, it's the aircraft as well. Most aircraft aren't stressed for rough field operations. You certainly aren't going to be able to operate a C-5, or other valuable and highly necessary aircraft from them.

The problem with roadway airfields is that only so many roads can be used. That means that whoever you are fighting knows which roads can be used, and targets them. Once they're damaged, no more airfields.

As to FOD, the military has issues with it on purpose built airfields (we used to have to have sweepers hit the ramp a couple times before F-16s started engines), what makes you think the best laid plans are going to get it all on a highway, where there is so much more?

reply to post by ownbestenemy


Not according to the DOT they weren't.

reply to post by Zaphod58


But you could put a C-17 (if you are landing on one of the more wide-birth interstates) or a C-130 down on them.

Originally posted by Zaphod58
reply to post by ownbestenemy

 

Not according to the DOT they weren't.

Huh...I was taught this back in 95...maybe I had a good teacher.

reply to post by ownbestenemy


You theoretically could. The C-17 has had issues with rough field landings in the past. But a C-17 doesn't give you the flexibility of a fleet of C-5s does. And your AWACS fleet will have issues with them as well as your tanker fleet. All highly necessary tools in a war.

reply to post by ownbestenemy


Or they were teaching a common myth. If you read up on the Eisenhower Interstate System there is nothing that says that they are required to have straight sections for runways. That has made the rounds for a long time however. I first heard it in the 80s, and believed it for a long time, but if you read the page i linked to earlier there is no requirement for dual use of the highways.

reply to post by Zaphod58


Roger...it was posted in theoretical. The amount of minor and minimal work say, to I-10 in Los Angeles to convert to a makeshift airfield (I know...there are 100s of fields most short-takeoff transports can utilize) would be viable if absolutely needed.

As for the dual use, we weren't spun the nonsense of 1 in 5 or 1 in 10 or whatever internet nonsense says today. We were taught it was for commerce in times of peace and transport in times of war.

reply to post by ownbestenemy


Sorry, thought you were talking dual use as in airfields. But yes they were built for transport and commerce.

As for short fields that only helps with aircraft built for short field ops.

Originally posted by Zaphod58
reply to post by Phoenix

 

There was talk of using the interstate as emergency runways, but it never amounted to anything. It's not just the roadways, it's the aircraft as well. Most aircraft aren't stressed for rough field operations. You certainly aren't going to be able to operate a C-5, or other valuable and highly necessary aircraft from them.

The problem with roadway airfields is that only so many roads can be used. That means that whoever you are fighting knows which roads can be used, and targets them. Once they're damaged, no more airfields.

As to FOD, the military has issues with it on purpose built airfields (we used to have to have sweepers hit the ramp a couple times before F-16s started engines), what makes you think the best laid plans are going to get it all on a highway, where there is so much more?

I fully agree that most modern US aircraft are not particularly suitable with exception of A-10 or Marine Harrier types and yes its kinda one way trip for C-5 or its liketo land on an interstate. I was refering to a time period like the early 60's to the early 70's where interceptor dispersal could be done.

Btw, in an all out major power shooting war I don't give C-5's long to live nor their fixed bases as I see them being used in SHTF for critical personnel, equipment evacuation of Mideast, Europe and Korea. Lovely lovely aircraft but I would not want to pilot in that kind situation. Big fat juicy target.

reply to post by Phoenix


The C-5 mission isn't to go into the combat zone though. They will be used to move large amounts of supplies to bases short of the fighting, and then anything that needs to go up to where the fighting is will go on C-130s and tactical transports. But the C-130s can't move the large amounts of fuel and weapons needed the large distances, in the short time. So you use a C-5 to get them from say the mainland, to Okinawa or Japan, and then C-130s and even a few C-17s to get them closer (if we're fighting in Asia).

But even in the 60s and 70s you had the same problems you have now. The aircraft weren't stressed for it and the engines would be at risk for FOD damage.

reply to post by Zaphod58

The problem with the whole "Interstate as runway" issue is that runways have to go at least generally in the direction of the winds.

Prevailing winds in the US are generally from the N/S/E/W/NW/NE/SW/SE...You are certainly not claiming interstates do not follow these directions, are you?

Add to that the fact that a two lane interstate wouldn't support the wingspan of any large aircraft (it would barely support the wingspan of most fighters).

The landing area does not need to support the wingspan, it merely needs to support the landing gear...the entire landing area area needs to accommodate the entire structure of the plane...most stretches of interstate in this country can certainly accommodate the wingspan of any plane currently flying in the world.

A two lane interstate (which most of them are) is required to have two lanes that are a minimum of 12 feet wide, the outside shoulder should be a minimum of 10 feet, and the inside shoulder a minimum of 4 feet. So we're looking at 38 feet of roadway, plus dividing wall, plus lights.

This is certainly not the picture of a vast majority of the miles of interstate in this country. It is a picture of interstates within densely populated sections of the country; however, most miles of interstate within the US are separated by at least four/six lanes worth of grassy median to allow for future improvements and widening...

Now add in the fact that their landing gear isn't stressed to handle landing on the rough surface of a roadway (if you've ever been down I-10 or I-12 and a few others, you know exactly what I mean), then you have a problem coming up. Even if you were able to successfully manage to land on the roadway, you wouldn't get off again, because all the debris on the road would FOD out the engines (which is why Russia builds intake doors onto their aircraft).

I have traveled every major interstate across the country. I am also a professional driver (Class A CDL). Currently addressing you from I-81, Toms Brook, VA...As I stated in my prior post, you most certainly would not want to make it an everyday practice of landing a plane on an interstate. We certainly have, in addition to all of the military airfields across the country, major international airports across the entire US, along with many national and regional airports, all entirely capable/better suited for handling aircraft of any size; however, if push to came to shove and martial law was proclaimed in this country, and it was necessary, planes could most certainly take off/land on these roads. No problem at all...

reply to post by Phoenix


I-285 running under the Hartsfield Airport runways in Atlanta...

A portion of the section between I-75 and I-85 on the south side of I-285 has been bridged with a new runway and taxiway of Hartsfield-Jackson Atlanta International Airport, the only interstate in the nation to a have an underpass on a runway (underpasses for taxiways do occur elsewhere).

I-285

Originally posted by totallackey

The landing area does not need to support the wingspan, it merely needs to support the landing gear...the entire landing area area needs to accommodate the entire structure of the plane...most stretches of interstate in this country can certainly accommodate the wingspan of any plane currently flying in the world.

You most certainly do have to allow for the wingspan. The road has to support the weight of the entire aircraft, but if there is not enough room for the wingspan then you certainly aren't landing there.

As for the rest, no I'm not saying that the interstates don't go in the direction of the winds, but you have to have the right interstate at the right time, which would mean that every one of them would have to be usable for a plane to land on.

I haven't seen any interstate that could support "any plane flying today". A C-5 has a 222 foot + wingspan, and has flown at over a million pounds. I haven't seen an interstate out there that could support them. You may get a C-17 into some of them, but certainly not most of them.

The problem boils down to room, and training. I've tossed out training, because that's irrelevant to the whole thing, but there is no way an interstate runway could "support any aircraft out there" and there is no way I'd even try landing fighters on US interstates.

reply to post by Phoenix


Interstates could very easily handle tanks. An M-1 weighs approximately 60 tons. A vast majority of bridges currently in place out in the Western US (Missouri, for instance) are rated at 60 tons or more.

On an interstate road, a tank could run at full speed for a very long time. If an enemy did the smart thing and targeted the bridges, taking them out, the tank would only need to slow down in order to traverse the barren area...

Since a tank utilizes nearly the same type of diesel power as a semi tractor, this means it could go very, very fast...

As far as the road being able to handle the weight, a lot of the grain/steel haulers around my home territory of NW Indiana used to haul weights in excess of 50 tons to/from the farm/mills to the grain elevators in Chicago/Gary/Detroit along I-80/94 and US 20.