Hi Everyone - I'm excited to join this forum and hope somone can educate me a bit on powering larger layouts. I started building a layout about 2 years ago. Naturally, I've grown it beyond the additional 4' X 8' plan, and I've have added some accessories recently and now feel it needs more power. As background, the mainline is about 70' with another 25' of sidings. It's all powered with just one 125W transformer through a loop of 14G copper wire below the platform using short connections to power "bus" via lock-ons every 6 feet or so. Even when running two TMCC-controlled trains on this loop, 125W seems sufficient to hold 18V during train operation. My problems started when I added the post-war automatic gateman and operating semaphore, both switched by insulated tracks and powered by track power. When the train trips the switch on either of these, I lose 1.5-2.0 V and the trains slow to a crawl, even if just running one train with no illuminated cars. My guess is the easy answer is to buy a ZW. But, I've got 4 other post-war era transformers, sitting idle including another matching 125W and 3 others rated at 90W. I'd hate to spend $400+ on a ZW if I can solve this problem with my existing power supplies. As you can see by name, with 4 young daughters, I need to save wherever possible. My thought is to connect both 125W transformers in parallel to the power bus (ensuring beforehand that they're in phase). Would this benefit? Any problems with that thought, such as blowing on-board electronics? Also, from the books I've read, it seems that the answer will be to create and power separate blocks. I have no problem doing this, and I guess I'd split the track into 2 blocks, put one accessory on each block, and power each block with a separate transformer. That seems to be what most people do, but I'm not sure why blocking is more advantageous than simply connecting the two transformers in parallel. Many thanks to anyone that can educate me. Guess I should've saved my physics books!