Blowing up the bridges - an engineereing house rule battalion level down

[Sensei.Tokugawa]

Greetings gentelmen.

Having had a few scenarios already under my belt, fought in different theaters and eras and moreover having been studying subject in some more detail by the means of reading and watching some available sources I have grown to doubt whether it is indeed fair historically and technically to allow indiscriminately all units capable in terms of the game engine to do the demolitions. Should it not be more accurate solution to restrict that to engineer subunits exclusively or at least units with some engineering capability? Certainly that would not extend to scenarios in which the units are of divisional size as they mostly have some engineering capability assigned so it's absolutely normal to deem them virtually fully prepared to perform such tasks. Don't You think - am I making or missing a point? ...

[Panama]

http://www.300thcombatengineersinwwii.com/bridges.html

This is an interesting site. Can't find my bookmark for the excellent Soviet engineer site I had.

As to your post. Lots of different kinds of bridges out there.

[Erik2]

What I do in my scenarios is label the bridges that are destroyable or not.
For instance like this:

)*( = prewired major bridge, any unit can destroy it
][ = major bridge, only engineer units may destroy it.
# = another useful symbol for a (minor) bridge

[fogger]

As an ex Ginger Beer (AFD) I have no trouble with small units destroying bridges. Many years ago my old sqn was tasked to destroy an old railway bridge and about 50 men took 4 days to drill and set up the charges. We droped two supporting columns as well as blowing the embankments. The bridge was about 20 meters above the old river bed and about 50 meters long (from memory). My beef is the speed at which bridges are repaired. A bridge across a major river which would take a couple of months to build yet in TOAW it can be repaired in one turn so in FITE that is 3.5 days. I would like to see bridges repaired at a % rate which could be attacked by air.

[winkelried]

sorry to disagree - here an example, that bridges can be blown quickly, but also rebuilt quickly:

object: pont de livron-sur-drôme 44°45'56.68"N 4°50'23.63"E
road: route nationale no 7
operation: retreat of german troops in august 1944 (operation dragoon)

blown on 16 august 1944 by FFI SAP (Section Atterrissages et Parachutages) under the command of Henri Faure aka Gérard with approx 20 FFI.

result: http://livronavenir.hautetfort.com/media/02/01/1385679029.jpg
bridge unusable for the retreating german 19th army. they had to ford a bit downriver.

repaired by U.S. troops http://livronavenir.hautetfort.com/media/01/00/1496603223.jpg
another example http://www.warwingsart.com/12thAirForce/bridgebuilders.html

seems that they used bailey bridge elements to rebuild bridges quite quickly. AFIK a bailey of 30 m is thrown within one hour (without enemy fire)http://www.40thengineers.org/Bridgephotos.htm in WW 2 they spanned up to 350 meters with baileys (using auxiliary supports).

a bit further down all bridges across the rhône river were destroyed by the USAAF. the Germans simply used barges and pontoons to create ferrys and ferried troops across the river (would be done by engineers in TOAW). the issue was not the time they would have needed to throw a bridge across the large river, but the fact, that ferries can be hidden from aircraft during the day.

in the early 80s we expected the soviets to force a large river (like the rhine) with all bridges blown within 6 to 12 hours including throwing pontoon/PMP bridges within 3 to 6 hours.

[winkelried]

some more information i found about bailey bridges in my library:
some of the bailey bridges were used in germany up to the 1960s as "permanent" bridges until the bridge could be re-built properly. e.g. in cologne the first bridge across the rhine (patton-bridge) was a bailey used until 1951.
the system is still extensively used today http://www.cnps.equipement.gouv.fr/article.php3?id_article=69

[Panama]

Yeah, it probably doesn't take more than a couple of squads to blow up a major bridge if they know what they're doing. Does every engineer squad know what they're doing? Probably not.

It also doesn't take less than a day to throw a bridge across a major river. I have the numbers someplace.

Something mildly irksome is that a unit can fix a bridge and then another unit can move across it as though it took zero time to put it up. Maybe it should be more of a combat function where time is consumed for any unit crossing the bridge during the turn it's fixed or a river is bridged. Maybe.

[winkelried]

ORIGINAL: Panama
Something mildly irksome is that a unit can fix a bridge and then another unit can move across it as though it took zero time to put it up. Maybe it should be more of a combat function where time is consumed for any unit crossing the bridge during the turn it's fixed or a river is bridged. Maybe.

that's a good point. deducting the time required to build the bridge.

[winkelried]

ORIGINAL: Panama

Yeah, it probably doesn't take more than a couple of squads to blow up a major bridge if they know what they're doing. Does every engineer squad know what they're doing? Probably not.

a question of colateral damage probably. i only rarely saw bridges blown including their embankments during ww2. this made reconstruction easier. it is a pretty daunting task to reconstruct a bridge including the embankments. probably easier to throw a pontoon/PMP bridge next to it.
blowing a segement or two of a bridge is a question of the amount of explosives available. looking at the job the FFI did at livrol: they probably had one or two guys trained in handling explosives and detonators. the rest was responsible to carry the explosives and the security. so we would be looking at 10-20 men carrying 5-20 kgs of explosives. something between 50 and 200 kgs which would make already quite a bang. probably enough to blow this segment.

[sapper32]

My take on bridge blowing is that it can be done quickly in fact as quick as driving a truck full of HE onto a bridge and detonating it massive waste of HE yes but quick,I think generaly it take a few hours for a troop of engineers thats say 25 trained men to set up a bridge demolition to a simple first stage then if time permits and the bridge dosent need to be blown immidiatly a couple more hours to set it up fully with multiple circuits and so on,
On the building side of things for modern scenarios bridges can be put across rivers in minutes that will take 70 tonnes plus the lenght of bridge can be quite long depending on the rivers depth and so on.WWII baily bridges and pontoon bridges could be constructed in hours and could span major rivers

[Curtis Lemay]

I would consider a Bailey bridge to be represented in the game as a Ferry-Bridging unit.

Repairing the bridge hex would be building a true bridge. Think "Bridge Over the River Kwai". And note that in the case of a rail bridge it can't be repaired with pontoons or such.

[winkelried]

ORIGINAL: sapper32
On the building side of things for modern scenarios bridges can be put across rivers in minutes that will take 70 tonnes plus the lenght of bridge can be quite long depending on the rivers depth and so on.WWII baily bridges and pontoon bridges could be constructed in hours and could span major rivers

PMP (Понтонно-мостовой парк) is a modern system which can take 60+ tons as bridge and 180 tons as a ferry and be built in a few hours.

[winkelried]

ORIGINAL: Curtis Lemay
I would consider a Bailey bridge to be represented in the game as a Ferry-Bridging unit.

Repairing the bridge hex would be building a true bridge. Think "Bridge Over the River Kwai". And note that in the case of a rail bridge it can't be repaired with pontoons or such.

The bailey system was something semi-permamnent - sometimes used for years. i think it is well presented with re-building bridges in TOAW.

the ferry-bridging unit needs to stay in place - could model, that you have limited amounts of bridge elements - although as an example the US built more than 89 kms of bailey bridges in Italy alone during WW2. a lot of those stayed there until some time after the war.

i remember also some provisional re-construction of railway bridges - still looking for some images and data for those. although you would not be able to run high-speed trains across, they could handle trains crossing very slowly.

[winkelried]

here we go: a railroad bridge in italy. see figure 11 Three, double-treble 60 ft. Bailey Spans constructed by 160 Railway Construction Company, R.E. from 3 October, 1943 to 15 October 1943, under Job Nº. 86/2 to cross the River Ofanto at St. S. Margherita di Savoia Ofantino. The original bridge was a masonry viaduct.

so it took one company to repair such a bridge within 12 days.

[winkelried]

just found this approx 7 minutes from arriving until first vehicle crosses video PMP although there seems one or two elements missing to fully reach the other shore

[sapper32]

This is the British armys latest close support bridging asset the Titan Armoured Vehicle Launching Bridge with a number 10 bridge which takes about 90 seconds to deploy and gives a max span of 24m and has a class of 70 tonnes

[Panama]

ORIGINAL: sapper32

This is the British armys latest close support bridging asset the Titan Armoured Vehicle Launching Bridge with a number 10 bridge which takes about 90 seconds to deploy and gives a max span of 24m and has a class of 70 tonnes

This might be a lot of fun on a windy spring day. [:D]

[sapper32]

ORIGINAL: Panama

ORIGINAL: sapper32

This is the British armys latest close support bridging asset the Titan Armoured Vehicle Launching Bridge with a number 10 bridge which takes about 90 seconds to deploy and gives a max span of 24m and has a class of 70 tonnes

This might be a lot of fun on a windy spring day. [:D]

Lol yeah they do wobble around a bit but never had to abort a launch in my career its a pretty versatile system for a fast crossing but wouldnt like to do it against a defended river crossing its a big target[:D]

[Sensei.Tokugawa]

Therefore I think it would depend on the era, the theater and the OpFors involved,eh?

[Sertorius1]

The following gives an indication as to how quickly German railway repair forces were able to make a destroyed line operable again:

11 July 1941 - 4th Pz Group reaches Porkhov;
18 July 1941 - 1st DRG train arrives same
23 August 1941 - 4th Pz Group reaches Luga;
23 August 1941 - as above
08 August 1941 - 16th Armee reaches Staraya Russa;
29 September 1941 - as above

This quote came from this website about the German state railroad in WWII. There is quite a bit of good information here.

http://www.feldgrau.com/dreichsbahn.html

Still, when it comes to repairing a railway bridge there should be a delay.

As a sidenote and I'm doing this from memory but I think it wasn't until June of 1942 the big railway bridge was repaired over the Lower Dnepr. The Soviets blew it back in September of 1941.