do MU cars have use sand for traction

[wborys]

obviously locomotives require sand for traction under various circumstances.
but do self-powered units also have sand distribution mechanisms?

[DutchRailnut]

no, it would require a whole fleet of laborers , just to serve all the cars.
because the FRA would require each and every car to work 24/7 when in train.

and with all wheels powered MU's have no problem with traction, just braking on leaf residue.

[talltim]

Depends where you are talking. Many MUs in the UK are fitted with sanding equipment and more are being retrofitted. However this tends to be for braking rather than accelerating as mentioned above. Some have 'one-shot' sanders for use in emergency braking.
This accident report http://www.raib.gov.uk/cms_resources/14 ... hester.pdf" onclick="window.open(this.href);return false; shows that a class of MU that was previously only fitted with 'one-shot' sanders is to be fitted with full sanding equipment
This one http://www.raib.gov.uk/cms_resources/11 ... negate.pdf" onclick="window.open(this.href);return false; shows what happens when communication breaks down and the 'army of laborers' doesn't fill the sandboxes

[Fan Railer]

The NJT Arrows do not have sanders.

[dowlingm]

http://en.wikipedia.org/wiki/Sandite" onclick="window.open(this.href);return false;
http://www.irishrail.ie/about-us/leaves-on-the-line" onclick="window.open(this.href);return false;

[pumpers]

http://en.wikipedia.org/wiki/Sandite
http://www.irishrail.ie/about-us/leaves-on-the-line" onclick="window.open(this.href);return false;

Here is what I thought was a remarkable diagram from the Irish report (page 12)- speed at different locations after applying the brakes on a downhill grade, and the track profile. It took over 3 miles (and I guess about 5 minutes) to stop the train from 65 mph, including about 2-1/2 miles in emergency. Once it got down to 25 mph, it got out of the specially-treated region, and went 1/2 mile without slowing down even 1 mph. Only stopped when it got to the end of the grade. Yikes.
JS

train speed and profile.JPG (48.33 KiB) Viewed 7098 times

[John_Perkowski]

Admin Note:

Moved to the self-propelled railcars forum, and cleaned up.

[edbear]

Budd RDCs had sand. You sure about MU cars? About 45-50 yrs ago on an MTA or MBTA PCC, a passenger lost his lunch and I saw motorman lift corner side seat by front door, scoop our some sand and cover the mess.

[Allen Hazen]

Not sure about m.u. cars on electrified "steam" railroads, but trams (a.k.a. streetcars, a.k.a. trolleys) in Melbourne (Australia) do. Large amounts of sand would accumulate on and beside the tracks at stops: the system used to have a rail-born vacuum cleaner (on the undercarriage of an old 4-wheel tram) to clean this up. (They now use vacuum cleaner trucks: much less picturesque!) Some of the newer, articulated, trams ("Light Rail Vehicles" -- there were at least two types in service when I moved away from Oz, one a French and one a German design, and I don't remember which ones are which) have sandboxes with transparent panels inside the car, so the level of sand in them can be checked easily from within.

[ex Budd man]

As built the Septa SL V cars were designed and (the first six cars) equipped with sanders. Some wonk decided to have them removed stating that inspecting and filling them every day would be an undo burden on shop and field personnel verses the supposed benefit. All Budd built CTA el cars were equipped with sanders. Some folks said that the sand would insulate the wheels from grounding the car but if that were true it would only be the lead axle set.

[DutchRailnut]

CTA is not under FRA rules so can let cars run without sand if need be, any railroad under FRA rules, would be burdened by servicing each and every car on a daily basis.
can you imagine the burden on say MN with over 800 cars ??