Many trains have a difficult time making it through the cross when in the turn (curved) position. Especially with a rake of rolling stock behind it. This is due to the very tight radius of the curve compared to a normal curve as shown in the picture below with my modified cross I tried to use in a tight spot on our original layout which eventually I removed due to all the derailments of many different trains. I copied this from Ucwepns layout where he has a one unit tram running around his town with no problems.
You are exactly right about the HD300 not having enough weight as I had that exact problem with mine especially when ascending the ramps with a rake of cars behind. At times the front end would lift up off the rail resulting in derailments. I installed a couple of shortened old Thomas weights in a perfect channel inside the engines shell. If taking the shell apart be very careful you don't lose the tiny nut that is used to hold the battery compartment door closed as it easily will fall out and if it falls out and be lost. By the same token, it can easily fall out when reassembling the shell so its best to make sure you do your work in an area or over something that if anything falls out it won't be lost.
You are exactly right about the HD300 not having enough weight as I had that exact problem with mine especially when ascending the ramps with a rake of cars behind. At times the front end would lift up off the rail resulting in derailments. I installed a couple of shortened old Thomas weights in a perfect channel inside the engines shell. If taking the shell apart be very careful you don't lose the tiny nut that is used to hold the battery compartment door closed as it easily will fall out and if it falls out and be lost. By the same token, it can easily fall out when reassembling the shell so its best to make sure you do your work in an area or over something that if anything falls out it won't be lost.
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